Ch3_LynchM

=Megan Lynch's Wikilog - Period 8 CP Physics - E. Burns - 2010 = toc

 There was a family riding home in two limos from a wedding and a drunk driver hit one of the limos which also caused te limo behind to crash as well. The family was was severely injured but five and seven year old girls were killed in the crash because they were so small in such a large car. The five year old got stuck in the wreckage while the seven year old was decapitated by her seat belt because she was buckled in and a asleep.
 * Homework **

A crash test. There is a teddy bear that flew out of the car. The front of the car and the driver got hurt but the kid in the back is fine.
 * What Do You See? **

In a car, you should be wearing a seat belt, make sure the brakes and airbags sre good and pay attention on the road.
 * What Do You Think? **

1. 2. a. Novice, Above 3. // (yes/no) // || //New Cars // // (1,2,3) // || //Vehicle Safety // People in vehicles are not the only ones in danger. A pedestrian can get hut by an automobile. Engineers can try to build the automobile so the pedestrians may be safer if they are hit by an automobile. A turning point in the history of automobile safety when Ralph Nader, an American attorney and political activist, wrote __Unsafe at Any Speed__ in 1965. A study of four-wheel drive vehicles found that the incidence of fatal 4WD crashes increased by 85 percent between 1990 and 1998. Automobiles with anti-lock brakes and four-wheel drive should be safer than automobiles without these features
 * Investigate **
 * //<span style="font-family: Arial,Helvetica,sans-serif;">Safety features // || //<span style="font-family: Arial,Helvetica,sans-serif;">Means of protection // || //<span style="font-family: Arial,Helvetica,sans-serif;">Pre-1960 cars //
 * __<span style="font-family: Arial,Helvetica,sans-serif;">seat belt __ || <span style="font-family: Arial,Helvetica,sans-serif;">During a crash one does not go flying into the windshield || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">head restraints __ || <span style="font-family: Arial,Helvetica,sans-serif;">So your neck doesn’t snap back when you stop short || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">front airbags __ || <span style="font-family: Arial,Helvetica,sans-serif;">To project the people driving and in the passenger seat from getting seriously injured || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">back up sensing system __ || <span style="font-family: Arial,Helvetica,sans-serif;">To see what is behind you in case of a blind spot || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">3 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">front crumple zones __ || <span style="font-family: Arial,Helvetica,sans-serif;">The space in the front of the car that when hit will crumble instead of you being directly hit || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">2 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">rear crumple zones __ || <span style="font-family: Arial,Helvetica,sans-serif;">Same as the front crumple zone for the back || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">2 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">side-impact beams in doors __ || <span style="font-family: Arial,Helvetica,sans-serif;">To reinforce the doors incase of a collusion on the side of the car || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">2 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">shoulder belts for all seats __ || <span style="font-family: Arial,Helvetica,sans-serif;">To keep one completely secure in the car || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">anti-lock braking systems (ABS) __ || <span style="font-family: Arial,Helvetica,sans-serif;">Helped maintain control/prevents || <span style="font-family: Arial,Helvetica,sans-serif;">Yes || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">tempered shatterproof glass __ || <span style="font-family: Arial,Helvetica,sans-serif;">In case of an accident the glass does not effect the people || <span style="font-family: Arial,Helvetica,sans-serif;">Yes || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">side airbags __ || <span style="font-family: Arial,Helvetica,sans-serif;">To project those on the car in case of a side collision || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">2 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">turn signals __ || <span style="font-family: Arial,Helvetica,sans-serif;">To notify other cars were you are going || <span style="font-family: Arial,Helvetica,sans-serif;">Yes || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">electronic stability control __ || <span style="font-family: Arial,Helvetica,sans-serif;">Helps resists rollovers || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">3 ||
 * __<span style="font-family: Arial,Helvetica,sans-serif;">energy-absorbing collapsible steering column __ || <span style="font-family: Arial,Helvetica,sans-serif;">Prevents chest trauma || <span style="font-family: Arial,Helvetica,sans-serif;">No || <span style="font-family: Arial,Helvetica,sans-serif;">1 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Physics Talk **

<span style="font-family: Arial,Helvetica,sans-serif;">1. Energy-absorbing collapsible steering column, shoulder belts for all seats, and front airbags <span style="font-family: Arial,Helvetica,sans-serif;">2. The growing number of kilometers traveled and some drivers think they can go faster if they are more protected
 * <span style="font-family: Arial,Helvetica,sans-serif;">Checking Up **

<span style="font-family: Arial,Helvetica,sans-serif;">1. <span style="font-family: Arial,Helvetica,sans-serif;">2. Wearing a helmet, Don’t where tight close, stay off busy roads, be aware of what’s around you, and wear colors that make you stand out if you are riding on a busy road. <span style="font-family: Arial,Helvetica,sans-serif;">3. Wear a helmet, be aware of the other racers and make sure your skates are smooth and sharp <span style="font-family: Arial,Helvetica,sans-serif;">4. Wear a helmet and other gear, don’t do any tricks you are not ready for, do not ride where there are many cars and wear the right shoes
 * Physics to Go**
 * <span style="font-family: Arial,Helvetica,sans-serif;">seat belt – FRST ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">head restraints – F ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">front airbags – FT ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">back up sensing system – R ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">front crumple zones – FT ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">rear crumple zones – RT ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">side-impact beams in doors – ST ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">shoulder belts for all seats – FRST ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">anti-lock braking systems (ABS) – T ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">tempered shatterproof glass –FRST ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">side airbags – ST ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">turn signals – RS ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">electronic stability control – T ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">energy-absorbing collapsible steering column - FRT ||

<span style="font-family: Arial,Helvetica,sans-serif;"> I would protect myself from an accident by making sure I have a safe car and that I do everything I can to utilize the car's safety
 * <span style="font-family: Arial,Helvetica,sans-serif;">What do you think now? **

<span style="font-family: Arial,Helvetica,sans-serif;">Section 2
I see someone flying over their car and the car that they hit into because they weren't wearing their seatbelt
 * What do you see?**

A car that travels much faster would need to have a stronger seat belt because it needs to keep you from flying forward.
 * What do you think?**

Seat belts and Newton's First Law of Motion. Newton's first law of motion is inertia. When a car hits a pole the first collision is when the car hits the pole. The pole exerts the force that brings the car to rest. The second collision is when the car stops but the body keeps moving. The structure of the car gives the force that brings the body to rest. The third Collision: the body stops, but the heart, the brain, and other organs keep moving. Force is the interaction between two objects that can result in an acceleration of either or both objects. Pressure is force per area where the force is normal to the surface Pressure is measured in N/m2
 * Physics talk**

1.Newton's first law of motion: an object at rest stays at rest and an object in motion stays in motion in a straight line with constant speed unless acted upon by a net, external force 2. The driver in a car crash remains in a state of motion when the car stops suddenly because their bodies and organs are moving 3. Newton’s first law and the three collisions: you body remains in motion because you are already in motion. It takes the seat belt to bring your body back to rest 4. Inertia: the natural tendency to remain at rest or to remain moving with constant speed in a straight line. 5. A broad band of material work better as a seat belt than a thin wire because it spreads out where it is slowing down your body.
 * Checking Up**

//Objectives:// What happens to a passenger involved in a car accident without and with a seatbelt? They will have nothing to hold them down and will fly in the direction the car goes when it is hit. What factors affect the passenger’s safety after a collision? Where they are on the road, where they are in relation to the car, and the damage the car huge. How would a seat belt for a racecar be different from one available on a regular car? The racecar is going so fast that if the stop short with a normal over the shoulder seatbelt they would get very hurt, so the have a full body one so that there is equal force from the belt on the person. //Hypothesis:// Respond to each of the above objectives fully. //Materials:// Clay, a ramp, 5 textbooks, and a spool of string. //Procedure:// 1. Make a clay figure and then place the figure in the cart. 2. Arrange a ramp so that the endstop is at the bottom of the ramp. 3. Adjust the height of the ramp to make a very shallow incline. 4. Send the cart down the ramp. 5. Very gradually increase the height of the ramp until significant “injury” happens to your figure. Make a note of this height. – 5 books, .2 meters 6. Fix your clay figure. Create a seatbelt for the figure and take a "Before" picture and post in your data table. 7. Send your cart and passenger down the ramp at the same height as in Step 5. Be sure to record your observations specifically and carefully. Take an "After" picture and post in your data table to supplement your written observations.
 * Investigate**

//Data and observations:// Injury Height with no seatbelt: __2 m__

as a result of the narrow wire. When the cart plunged forward, he moved forward as well, pushing against his wire restraint. We observed lacerations to his shoulder and legs. || 5 || the slant, he was in good condition and the ribbon was a decently sturdy seatbelt. After released down the slant the seatbelt restricted the person from falling out of the car. The damage wasn't very severe, he might have went through the windshield. Only a broken arm and maybe some injuries on the back/neck. Overall the seatbelt protected the clay person from death but no serious injuries. || 2 ||
 * Type of Seatbelt || Before Picture || After Picture || Description and Observations || Group ||
 * Thread || [[image:Photo_293.jpg width="187" height="145"]] || [[image:Photo_296.jpg width="192" height="144"]] || The seatbelt holds him but the thread is so small so it puts too much pressure in small area which digs into his body. || 1 ||
 * Wire || [[image:Photo_11.jpg width="192" height="144"]] || [[image:Photo_12.jpg width="192" height="144"]] || The clay passenger suffered cuts
 * String || [[image:beforeclayman!.jpg width="192" height="144"]] || [[image:afterclaymannn.jpg width="192" height="144"]] || The clay man fell forward but no injuries but he was not thrown from the car like he was without being thrown from the car || 6 ||
 * Yarn || [[image:Photo_on_2011-01-31_at_14.36.jpg width="192" height="144"]] || [[image:Photo_on_2011-01-31_at_14.37.jpg width="192" height="144"]] || The little clay man was sent flying down the incline with a two-point seat belt made of yarn around his waist and across his body and shoulder, and crashed into the end, without significant injury. No cuts could be seen from the force of the yarn on the man and no body parts were missing or out of place. The cart hit the end of the track and the little clay man did not move sitting in place where I had placed him on the cart. || 4 ||
 * Ribbon || [[image:before.png width="181" height="244"]] || [[image:after.png width="310" height="160"]] || Before we let our clay person go down
 * 1-in masking || [[image:tapeseatbeltan.jpg width="192" height="144"]] || [[image:afteranseat.jpg width="192" height="144"]] || The clay model was sent down the incline/ramp with a seat-belt made out of tape. The tape was wrapped around his waist and than pulled over his shoulder. The seat-belt allowed the clay model to go down the incline without ending up out of the cart and with significant injuries. The clay model was still held in by the seat-belt by the end of the trial, so in all the tape seat belt worked. || 3 ||

//Questions:// 1. Inertia: the tendency an object has to remain at rest or to remain moving in a constant speed in a straight line Force: an interaction between two objects that results in acceleration Pressure: force per area where the force is normal to the surface (N/m^2) 2. The passenger wants to keep moving straight 3. Organs 4. They want to keep moving and the body forces them to stop 5. An object with a larger surface area to spread the force needed to slow the body down. If it wasn't thick, it would dig into the person. 6. Collision 1: The pole is at rest and will remain at rest. It has to exert an external force on the object in motion, car, to bring it to rest Collision 2: The body wants to remain in motion and needs an external force to bring it to rest Collision 3: The body, an external force, brings the organs to rest. 7. A broad band spreads the pressure used to slow down your body. A narrow wire applies too much force to one area. //Conclusion:// __· Using Newton's First law of Motion, explain why a seat belt is an important safety feature in a vehicle. What factors affect the effectiveness of a seatbelt? What would you need to consider when designing a seatbelt for a race car? Use specific observations from this investigation to support your answers to these questions.__ Seat belts are very important because they keep your body from flying out of a car in an accident. If the seat belt is too thin it could end up hurting you instead of helping. You need to consider the speed of the car when making its seat belt. The faster it goes, the more pressure will be needed to slow the person down. In a race car, the seat belts would have to be much larger to spread the pressure.
 * Read the Physics Talk p268 - 271 before answering the following questions. *

__· Explain at least 1 cause of experimental error. Be sure you describe a specific reason.__ You could create an error by thinking that an injury from getting hit my the cart was due to the clay person flying from the cart.

__· How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?)__ I would make sure that the clay people are very flat so it is much easier to see the results of the accident.

Section 3
How does an air bag protect you during an accident? **Hypothesis:** Respond to the objective fully. In an accident, an air bag will apply more force to help your body slow down. **Materials:** List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video). > 1. Measure the length of your egg #1. Measure the mass of your egg. Record this information. //.0582kg// 2. Place an egg in a ziplock bag, squeezing out all of the air in the bag before sealing. 3. Hold a ruler up on the table vertically. Hold the egg vertically at the 2 cm mark. (Keep the excess bag on top.) Drop it. Record your observations. //5.5cm// 4. Hold the egg the same exact way at the 4-cm mark and repeat. Continue this process until the egg shell is slightly cracked. 5. Continue until the egg is smashed and the yolk leaks out. Measure the amount of egg still undamaged. How much of the egg is smashed? Be sure to record detailed observations. //1.5 cm were damaged// 6. Fill a bowl with flour and place the bowl inside of the box lid. 7. Measure the length of your egg #2. Measure the mass of your egg. Record this information. //.0587 kg// 8. Drop the egg from the smash height (Step 5). Measure the amount of egg sticking up out of the rice bed. How much of the egg is buried in the rice? Also, record your observations. 9. Repeat this, increasing the height in 2-cm increments until the egg is cracked, and then smashed.
 * Objective:**
 * Eggs
 * Meter Stick
 * Flower in a bowl
 * Box
 * Procedure:**
 * We will drop the egg 2cm higher each time when it lands on the table until it cracks
 * When dropping it into the flower, we will start at the distance it took the egg to break on the table and go up 10cm each time


 * Data and observations:** Add more columns/rows as needed.
 * **Egg #** || **Drop Height (cm)** || **Cracked or Smashed?** || **Description and Observations** || **GPE (J)** || **Work (J)** ||
 * 1 || 2 || slightly cracked || really thin crack || .01 || .01 ||
 * 1 || 4 || crack widened || still thin but longer || .02 || .02 ||
 * 1 || 6 || cracked more and dented || it grew || .03 || .03 ||
 * 1 || 8 || dent increased slightly || cracked more || .05 || .05 ||
 * 1 || 10 || crack increasing || it is going up the egg || .06 || .06 ||
 * 1 || 12 || cracked more || yolk is coming out || .07 || .07 ||
 * 1 || 14 || extremely cracked || yolk is coming out || .08 || .08 ||
 * 1 || 16 || smushed || entire bottom is flat || .09 || .09 ||
 * 1 || 18 || smushed || still flat || .1 || .1 ||
 * 1 || 20 || cut in half || almost fully smashed || .11 || .11 ||
 * 1 || 22 || smashed || yolk is out || .12 || .12 ||


 * 2 . || 22. || none . || The dent size is 1 cm and no crack. || ** .122 ** ||
 * 2 || 32 || none || The dent size is now 1.5 cm. || .179 ||
 * 2 || 42 || none || The dent size is 1.8 cm. || .234 ||
 * 2 || 52 || none || The dent size is 2 cm. || .290 ||
 * 2 || 62 || none || The dent size is 2.5 cm. || .346 ||
 * 2 || 72 || none || The dent size is 3 cm. || .346 ||
 * 2 || 82 || none || The dent size is 3 cm. || .458 ||
 * 2 || 92 || none || The dent size is 3 cm again. || .513 ||
 * 2 || 102 || none || The dent size is 3 cm. || .569 ||
 * 2 || 200 || smashed || We missed the target and the egg smashed. || 1.15 ||

1. 2.
 * Calculations:** Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results.

3. a. b. c.

1. The egg represents a person’s head in a collision when they hit the air bag. The table shows the amount of force it takes for the egg to crack with and without the flower which represents the air bag. 2. a) Kinetic Energy: energy possessed by a moving body b)Work: the amount of force applied on an object over a distance 3. The objects mass and velocity 4. Kinetic energy increases 5. The farther the distance, the more force is needed to stop the object from moving because, of Newton’s first law. Since the difference in distance is greater the farther away the egg was, the faster it was moving. 6. A soft landing area made it easier to stop the passenger from moving because it lessens the pressure when it compresses.It lessens the force because it compresses and gradually slows the passenger down. 7. Since energy can't be created or destroyed, there is no way of getting rid of pressure but by using a cushion, the pressure is dispersed on a larger area.
 * Questions**

<span style="font-family: Arial,Helvetica,sans-serif;">1. An air bag protects you just as the flower protected the egg. It lessens the impact by applying pressure on more then one single spot. It also transfers the pressure to a larger spot, making it lessen. <span style="font-family: Arial,Helvetica,sans-serif;">2. You could measure the distance of the egg drop from the top of the egg instead of the bottom <span style="font-family: Arial,Helvetica,sans-serif;">3. I would use another cushion other then flower; it was too difficult to measure and it made a mess.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Conclusion: **

<span style="font-family: Arial,Helvetica,sans-serif;">Section 5
<span style="font-family: Arial,Helvetica,sans-serif;">**Investigate**

<span style="font-family: Arial,Helvetica,sans-serif;">//Objective:// A small sports car hits a heavy truck in a collision. What factors determine the outcome for the passengers of the two vehicles? Which driver will sustain worse injuries? Why?

<span style="font-family: Arial,Helvetica,sans-serif;">How fast each is going at the time of the collision and the mass of each vehicle. The driver in the small car will sustain worse injuries because the small is not as strong as the strong as the truck and is easier to move.

<span style="font-family: Arial,Helvetica,sans-serif;"> //Materials:// List any materials used and draw a labeled diagram of your set-up (alternatively, include a snapshot or video).

<span style="font-family: Arial,Helvetica,sans-serif;">Ramp

<span style="font-family: Arial,Helvetica,sans-serif;">2 500g masses <span style="font-family: Arial,Helvetica,sans-serif;"> Two carts

//<span style="font-family: Arial,Helvetica,sans-serif;"> Procedure: //


 * 1) <span style="font-family: Arial,Helvetica,sans-serif;">Place a cart on the middle of the track with the spring to the right. Call this the "target cart."(blue) Place a second identical cart on the right end of the track. Call this the "Bullet cart".
 * 2) <span style="font-family: Arial,Helvetica,sans-serif;">Push the bullet cart very gently towards the target cart so that they collide, with the spring between them.
 * 3) <span style="font-family: Arial,Helvetica,sans-serif;">Repeat step 2 several times, giving the bullet cart a bigger push each time. Record your observations.
 * 4) <span style="font-family: Arial,Helvetica,sans-serif;">Add 500-g to each cart and repeat the process. Record your observations and compare the results to the first set of collisions.
 * 5) <span style="font-family: Arial,Helvetica,sans-serif;">Remove the mass from the target cart and repeat the above steps.
 * 6) <span style="font-family: Arial,Helvetica,sans-serif;">Add the mass to the target cart and remove the mass from the bullet cart, and repeat.
 * 7) <span style="font-family: Arial,Helvetica,sans-serif;">Get the "Mystery" cart from your teacher. Determine the relative mass of the cart by putting it through a sequence of collisions.

<span style="font-family: Arial,Helvetica,sans-serif;"> //Data and observations:// Add more columns/row as needed.

<span style="font-family: Arial,Helvetica,sans-serif;">Questions: <span style="font-family: Arial,Helvetica,sans-serif;">1. What is a real-life collision that the collisions in this investigation could represent? <span style="font-family: Arial,Helvetica,sans-serif;">A rear end collision <span style="font-family: Arial,Helvetica,sans-serif;">2. How well did observing collisions enable you to compare the masses of the carts in the last step? <span style="font-family: Arial,Helvetica,sans-serif;">Since the cart did nit move very much we concluded that they mass were very similar if not the same.,1250g. <span style="font-family: Arial,Helvetica,sans-serif;">3.What happened after the collision as the masses changed? <span style="font-family: Arial,Helvetica,sans-serif;">When the target cart gains mass, it cart went farther <span style="font-family: Arial,Helvetica,sans-serif;">4. Define the term momentum. <span style="font-family: Arial,Helvetica,sans-serif;">The product of the mass and the velocity of an object <span style="font-family: Arial,Helvetica,sans-serif;">5. Which object has greater momentum, a butterfly traveling at 16 km/h or an eagle traveling at the same speed? <span style="font-family: Arial,Helvetica,sans-serif;">An eagle <span style="font-family: Arial,Helvetica,sans-serif;">6.How does the transfer of momentum occur? <span style="font-family: Arial,Helvetica,sans-serif;">In a collision <span style="font-family: Arial,Helvetica,sans-serif;">7. Use momentum to describe what would happen if a skaterboarder was hit by a car. <span style="font-family: Arial,Helvetica,sans-serif;">If a skateboarder, the force of the collision on the skateboarder would damage him much more then the car.
 * __<span style="font-family: Arial,Helvetica,sans-serif;">Bullet Cart __ || __<span style="font-family: Arial,Helvetica,sans-serif;">Target Cart __ || <span style="font-family: Arial,Helvetica,sans-serif;">A__pplied force__ || <span style="font-family: Arial,Helvetica,sans-serif;">Description and Observations ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Small || <span style="font-family: Arial,Helvetica,sans-serif;">The bullet cart pushed the target cart a little then it stopped ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Little more || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart traveled further then before ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Medium || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart went fast and far while the bullet cart stopped movie on impact ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart went fast and far while the bullet cart stopped movie on impact ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">With the same light push as the 750g carts the target cart moved farther. ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Medium || <span style="font-family: Arial,Helvetica,sans-serif;">With the same medium push as the 750g carts the target cart moved farther. ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">With the same hard push as the 750g carts the target cart moved farther. It also went father because after hitting the stop point the target cart bounced back ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart went a lot further then it has before with just a light push ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Medium || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart went further and faster then before with a medium push and the bullet cart kept moving as well ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart went further and faster then any of the before hard pushes. The bullet cart also did not stop moving ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart moved and the bullet cart followed. The bullet cart went back then forward again ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Medium || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart did not traveled as far and the bullet cart went backwards ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart moved far but went slower and the bullet cart moved backward after hitting the target. ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Mystery || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart did not move far and the mystery cart moved back a small bit ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">Mystery || <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">The target cart moved far and fast and the Mystery did not move after impact. ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Mystery || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">The mystery cart moves as far but slowly and the bullet cart stops moving ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1250g || <span style="font-family: Arial,Helvetica,sans-serif;">Mystery || <span style="font-family: Arial,Helvetica,sans-serif;">Hard || <span style="font-family: Arial,Helvetica,sans-serif;">The mystery cart moved far but fast and the bullet stopped ||  ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">750g || <span style="font-family: Arial,Helvetica,sans-serif;">Mystery || <span style="font-family: Arial,Helvetica,sans-serif;">Light || <span style="font-family: Arial,Helvetica,sans-serif;">The mystery cart moves as far but slowly and the bullet cart stops moving ||  ||

<span style="font-family: Arial,Helvetica,sans-serif;"> **Conclusion:** <span style="font-family: Arial,Helvetica,sans-serif;"> 1. Based on the relative amounts of momentum, what is the outcome of a head-on collision between a heavy truck and a small sports car if both have the same speed? <span style="font-family: Arial,Helvetica,sans-serif;">If one has a mass of 1000 kg and travels at 20 m/s, their momentum is 20,000. A 10,000 kg truck traveling at the same speed has a momentum of 200,000. In a head on collision, their momentum is 220,000 <span style="font-family: Arial,Helvetica,sans-serif;">2. Explain at least 1 cause of experimental error. Be sure you describe a specific reason. <span style="font-family: Arial,Helvetica,sans-serif;">One cause of experimental error would be if you didn't chance the speed in which the first cart traveled. <span style="font-family: Arial,Helvetica,sans-serif;">3. How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?) <span style="font-family: Arial,Helvetica,sans-serif;">I would improve the results of this lab by using a stop watch to see the difference of speed.

<span style="font-family: Arial,Helvetica,sans-serif;"> 1. They reach the same speed <span style="font-family: Arial,Helvetica,sans-serif;"> 4. They have more momentum and are harder to push down and push down everyone else easily <span style="font-family: Arial,Helvetica,sans-serif;"> 5. Their momentum <span style="font-family: Arial,Helvetica,sans-serif;"> 6. 1 m/s
 * <span style="font-family: Arial,Helvetica,sans-serif;">Physics To go **

<span style="font-family: Arial,Helvetica,sans-serif;">Section 6
<span style="font-family: Arial,Helvetica,sans-serif;"> What physics principles do the traffic-accident investigators use to "reconstruct" the accident?
 * <span style="font-family: Arial,Helvetica,sans-serif;">Objective **

Two carts, ramp, 4 500g weights, 2 250g weights, a motion detector, and a laptop
 * <span style="font-family: Arial,Helvetica,sans-serif;"> Materials: **


 * <span style="font-family: Arial,Helvetica,sans-serif;"> Procedure: **
 * 1) <span style="font-family: Arial,Helvetica,sans-serif;">Place a motion detector at the right end of a track. Open up data studio. Dump "Velocity" into "Graph" display, and enlarge this.
 * 2) <span style="font-family: Arial,Helvetica,sans-serif;">Place a cart on the middle of the track with the velcro to the right. Call this the "target cart." Place a second identical cart on the right end of the track. Call this the "Bullet cart".
 * 3) <span style="font-family: Arial,Helvetica,sans-serif;">Click "Start" on Data Studio, and then push the bullet cart very gently towards the target cart so that they collide and stick together. You may need to practice this a few times. Be sure to get your body out of the way of the motion detector!
 * 4) <span style="font-family: Arial,Helvetica,sans-serif;">Examine the graph produced by the motion detector. Using the Smart Tool, find the velocity right before and right after the collision. Record this in your data table.
 * 5) <span style="font-family: Arial,Helvetica,sans-serif;">Vary the masses of the carts and repeat the process 5 times.

<span style="font-family: Arial,Helvetica,sans-serif;">**Data and observations:** Add more columns/row as needed.
 * **<span style="font-family: Arial,Helvetica,sans-serif;">Mass of Bullet Cart (kg) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Mass of Target Cart (kg) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Speed of Bullet Cart (m/s) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Speed of Target cart (m/s) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Combined masses (kg) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Final Velocity of both carts (m/s) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Initial Momentum of the bullet cart (kgm/s^2) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Initial Momentum of the target cart for each (kgm/s^2) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Sum of the Initial Momenta of the two carts (kgm/s^2) ** || **<span style="font-family: Arial,Helvetica,sans-serif;">Final Momentum of the combined carts ** ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.499 || <span style="font-family: Arial,Helvetica,sans-serif;">.501 || <span style="font-family: Arial,Helvetica,sans-serif;">.85 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1 || <span style="font-family: Arial,Helvetica,sans-serif;">.33 || <span style="font-family: Arial,Helvetica,sans-serif;">.424 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.33 || <span style="font-family: Arial,Helvetica,sans-serif;">.33 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.999 || <span style="font-family: Arial,Helvetica,sans-serif;">.501 || <span style="font-family: Arial,Helvetica,sans-serif;">.56 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1.5 || <span style="font-family: Arial,Helvetica,sans-serif;">.36 || <span style="font-family: Arial,Helvetica,sans-serif;">.559 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.36 || <span style="font-family: Arial,Helvetica,sans-serif;">.54 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.499 || <span style="font-family: Arial,Helvetica,sans-serif;">1.001 || <span style="font-family: Arial,Helvetica,sans-serif;">.71 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1.5 || <span style="font-family: Arial,Helvetica,sans-serif;">.25 || <span style="font-family: Arial,Helvetica,sans-serif;">.354 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.25 || <span style="font-family: Arial,Helvetica,sans-serif;">.38 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.499 || <span style="font-family: Arial,Helvetica,sans-serif;">1.251 || <span style="font-family: Arial,Helvetica,sans-serif;">.80 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1.75 || <span style="font-family: Arial,Helvetica,sans-serif;">.29 || <span style="font-family: Arial,Helvetica,sans-serif;">.399 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.29 || <span style="font-family: Arial,Helvetica,sans-serif;">.51 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">1.249 || <span style="font-family: Arial,Helvetica,sans-serif;">.501 || <span style="font-family: Arial,Helvetica,sans-serif;">.56 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1.75 || <span style="font-family: Arial,Helvetica,sans-serif;">.35 || <span style="font-family: Arial,Helvetica,sans-serif;">.699 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.35 || <span style="font-family: Arial,Helvetica,sans-serif;">.61 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.999 || <span style="font-family: Arial,Helvetica,sans-serif;">1.001 || <span style="font-family: Arial,Helvetica,sans-serif;">.67 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">2 || <span style="font-family: Arial,Helvetica,sans-serif;">.30 || <span style="font-family: Arial,Helvetica,sans-serif;">.669 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.30 || <span style="font-family: Arial,Helvetica,sans-serif;">.60 ||
 * <span style="font-family: Arial,Helvetica,sans-serif;">.749 || <span style="font-family: Arial,Helvetica,sans-serif;">.751 || <span style="font-family: Arial,Helvetica,sans-serif;">.85 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">1.5 || <span style="font-family: Arial,Helvetica,sans-serif;">.46 || <span style="font-family: Arial,Helvetica,sans-serif;">.637 || <span style="font-family: Arial,Helvetica,sans-serif;">0 || <span style="font-family: Arial,Helvetica,sans-serif;">.46 || <span style="font-family: Arial,Helvetica,sans-serif;">.69 ||

<span style="font-family: Arial,Helvetica,sans-serif;"> //Calculations:// Show equation(s), numbers plugged in, and answer with correct units. Add columns in your data table to include these results. <span style="font-family: Arial,Helvetica,sans-serif;">1. Find the initial momentum of the bullet cart for each trial. <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;">2. Find the initial momentum of the target cart for each trial. <span style="font-family: Arial,Helvetica,sans-serif;">3. Find the sum of the initial momenta of the two carts for each trial. <span style="font-family: Arial,Helvetica,sans-serif;">0+.33=.33

<span style="font-family: Arial,Helvetica,sans-serif;">4. Find the final momentum of the combined carts for each trial? <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;"> *Read the Physics Talk p312 - 315 before answering the following questions. * Questions: <span style="font-family: Arial,Helvetica,sans-serif;">1. Compare the initial momenta (calc 3) to the final momentum (calc 4). (Allow for minor variations due to uncertainties of measurement.) <span style="font-family: Arial,Helvetica,sans-serif;">Similar

<span style="font-family: Arial,Helvetica,sans-serif;">2. List the 6 types of collisions (top of page 312) and a brief description. <span style="font-family: Arial,Helvetica,sans-serif;">Type 1: One moving object hits a stationary object and both stick together and move off at the same speed <span style="font-family: Arial,Helvetica,sans-serif;">Type 2: Two stationary objects explode by the release of a spring between them and move off in opposite directions <span style="font-family: Arial,Helvetica,sans-serif;"> Type 3: One moving objects hits a stationary object. The first objects stops, and the second object moves off <span style="font-family: Arial,Helvetica,sans-serif;">Type 4: One moving object hits a stationary object, and both move off at different speeds <span style="font-family: Arial,Helvetica,sans-serif;">Type 5: Tow moving objects collide, and both objects move different speeds after the collision <span style="font-family: Arial,Helvetica,sans-serif;">Type 6: Two moving objects collide, and both objects stick together and move off at the same speed.

<span style="font-family: Arial,Helvetica,sans-serif;">3. Which types of collisions are definitely inelastic? How do you know? <span style="font-family: Arial,Helvetica,sans-serif;">3, 4, and 5 because their KE would not be the same.

<span style="font-family: Arial,Helvetica,sans-serif;">4. Which types of collisions are definitely elastic? How do you know? <span style="font-family: Arial,Helvetica,sans-serif;">1,2, and 6 because their KE would be the same.

<span style="font-family: Arial,Helvetica,sans-serif;">5. Define the law of conservation of momentum. <span style="font-family: Arial,Helvetica,sans-serif;">Momentum cannot be created or destroyed but can be transferred within a closed system.

<span style="font-family: Arial,Helvetica,sans-serif;">6. Use the law of conservation of momentum to describe what happens when a cue ball hits the 15 balls in the middle of the pool table? The momentum from the cue ball gets transferred into the other balls, causing them to break apart.

<span style="font-family: Arial,Helvetica,sans-serif;">**Conclusion:** 1.Based on the law of conservation of momentum, how can the traffic-accident investigators use to "reconstruct" the accident? What does it mean to "conserve" momentum? <span style="font-family: Arial,Helvetica,sans-serif;">Traffic accident investigators can conserve momentum by lessening the speed limit. By doing this, they are making cars take more time and conserving momentum.

<span style="font-family: Arial,Helvetica,sans-serif;">2. Explain at least 1 cause of experimental error. Be sure you describe a specific reason. <span style="font-family: Arial,Helvetica,sans-serif;">One error would be using the wrong side of the cart

<span style="font-family: Arial,Helvetica,sans-serif;">3.How would you improve the results of this lab? (In other words, what would you change about the materials or procedure to eliminate or reduce the experimental error you describe above?) <span style="font-family: Arial,Helvetica,sans-serif;">To improve this lab, I would make sure that each ramp is level to make sure the results are correct.