5/20 Conservation of Energy/ Conservation of Angular Momentum

Purpose: To prove conservation of energy and angular momentum using a collision with a meter stick and clay.

Procedure:
To prove conservation of momentum we needed to demonstrate a rotational collision. To do this, we set up a meterstick, pivoted at 1.3 cm, to collide with clay where the clay sticks to the meter stick stick after. We then set up a camera to capture the collision. Once we had the meterstick-clay system setup, we raised the meter stick to the horizontal position and let it fall straight down (FIGURE (1)).

FIGURE (1)

We recorded the collision (video to right) and analyzed it in LoggerPro (FIGURE (3)). Our analysis concluded that the meter stick-clay system pivoted to a height of 27.79 cm above its original position. 

FIGURE (3)

We then calculated the height with energy and momentum (FIGURE (4)). We first had to calculate the initial angular velocity of the meter stick using conservation of energy. Once we had the initial angular velocity of the stick we used angular momentum to calculate omega right after the meter stick hit the clay. We then used energy again to solve for the final height it would reach. We came up with a value of 0.286 m.

FIGURE (4)

Conclusion:
Overall, the experiment seemed to prove the theory we had correct. Out calculated value was about 2% off from out experimental value, which is good since there could have been a few sources of error. One source of error could be from the camera. The camera is not very high quality and had a slight fish-eye so the image is slightly distorted. The image is also not very focused so it is difficult to pin-point the exact origin and the final position. There also might have been some friction in the system.