Lab 20: Conservation of Linear and Angular Momentum

Lab 20: Conservation of Linear and Angular Momentum

Date Completed: November 21st 2016

Lab Members:
Jarrod Griffin
Christina Vides
Enio Rodriquez

Introduction:

In this experiment we investigate conservation of different momentums. In order to do this we rolled a ball onto a moment arm that was on a freely rotating disk. This lab was done as a class, so almost all data will be the same between students. 

Procedure/Apparatus: 

We started this lab by first measuring almost all aspects of the experiment, including heights, masses, and radii. We then set up the ramp ball system on the edge of a table, and found its velocity as it left the ramp. We then placed the ramp so that it would hit the moment arm of the disk and the ball would stick, transferring all of its linear momentum into rotational momentum. We recorded the rotations of the disk. We then calculated our data and made a prediction of what our experimental values would be. 

Measured Data:

We found alpha by taking the average alpha from graphs in Logger Pro that are pictured below.

Calculated Data:

We used the conservation of momentum theorems to derive an expression where the only unknown variable was W. This allowed us to calculate what W would be in a perfect world. We can then compare this to actual data we have. 

Conclusion:

This lab was very successful. Our percent errors were both below 5%, meaning that our setup was very good with very little outside involvement such as friction and other resisting forces. This lab showed us that the conservation of momentum theorems hold true even in the real world where outside forces act upon the system. Some uncertainties in the system are all measurements we took. We took almost all measurements with a meter stick, something that can only be so accurate.