Purpose-Procedure (and data below)

1. Purpose: The purpose of this lab is to investigate conservation of momentum and the transfer of momentum with objects of the same mass but with varying velocities in elastic collisions.
   Equipment:
   Air Track
   Air Track cars (same mass)
   Photo-gate timers
   Laptop
   Meter Stick
   Procedure:
   Set up the Air Track
   Measure the mass and length of each Air Track car.
   Set up the Photo-gate timers- each timer should be the same distance away from each end of the track.
   Place one car in the middle of the track in between the two timers, and make sure it is at rest.
   Place the second car before the first photo-gate timer at the end of the track.
   Using the photo-gate timers, push the second car, making sure you release the push before the photo-gate timer. Measure the velocity of the first car before and after the collision, and measure the velocity of the second car after the collision using the photo-gate timers.
   Repeat steps 4-6.
   Now, place each car at the end of the track.
   Have one person (this may take more than one try to get near accurate results) push each car, at the same time, with the same speed towards each other.
   Using the Photo-gate timers, make sure the speeds of the cars are very similar after the push coming towards each other, and if they are, use the timers to measure the speeds of each car after the collision.
   Repeat steps 8-10.
   For the third scenario, the Photo-gate timers may need to be moved, one shifted so that both cars can fit before going through the timer, and the other moved more towards the opposite end of the track.
   Now, place both cars at the end of the track with more space between the end of the track and the timer.
   Have one person push the car in front, very slowly, so that its speed is recorded when it passes through the first photo-gate timer.
   Then, have that person push the second car with a higher velocity, so that its speed is not only measured by the first photo-gate timer, but so the two cars collide between the two timers.
   After the collision have one person at the opposite end of the track than where the cars were pushed, and immediately after the front car goes through the timer so that its velocity after the collision is measured, have the person pick up this car off the track.
   Next, allow the second trailing car to go through the second timer and have its velocity be measured after the collision.
   Repeat steps 12-17.