Wednesday, May 10, 2017

Ballistic Pendulum Lab

May 1,2017
Ana Leyva, Jonathan Goei
The purpose of this lab was to determine the firing speed of a ball from a spring loaded gun, However since we don't have anything to help us determine the speed of the ball, we will have to calculate this using thing that we were able to calculate such as the height to which the ball rises, and the angle to which it rises.

There were two parts for this experiment in the first part we calculated the angle to which our box went to when the ball was fired. For the second part we used our calculated velocity to figure out how far away our ball would land if we were to shot it and there was nothing to stop it.
For the first part we started off by measuring the mass of the ball and the block. Then we leveled the base of the apparatus and we leveled the hanging block. We then got ready to fire the ball by pulling back the notch to the third position. We then made sure that the angle indicator was at zero degrees and then we pushed a lever that released the ball and fired it into the block. We then repeated this four more times in order to get 5 different angles that were hopefully close to each other. We then got these angles and got an average. After this we did some calculation that helped us determine the speed at which the ball was fired. In order to do this we first had to think about the conservation of momentum in inelastic collisions in order to find a way to calculate the velocity at which the ball was fired. We did this by first taking in to account the momentum from when the ball is fired to the time when the ball hits the block. We then used the law of conservation of energy which helped us calculated the velocity of the block and ball as it was rising. In order to figure this out we fist needed to find out the max height that the block reaches. We found this out by using the length of the stings that suspended the block and the angle to which it rose. This height allowed us to find the velocity of the box and the ball together which in turn helped us find out the initial speed of the bullet.

Measured Data






Calculated Data and Propagated Uncertainties 





In conclusion our calculation were off even when we took into account the uncertainties in our calculations. This could be due to many outside factors like the movement of the table when we were doing the experiments. It could also be due to the fact that maybe our apparatus wasn't as leveled as we thought it was. Then there is always human error maybe we didn't measure things as closely as we thought we did. 





No comments:

Post a Comment