30 October 2014: Angular Acceleration Part 1 Lab 15

Objective:
The purpose of this lab is to be able to measure angular acceleration. We will also discover if any factors could affect angular acceleration.

Set Up:

This picture illustrates the setup of this lab. There will be two disks that are allowed to rotate freely against each other in  Pasco rotational sensor. The disks will either be made of aluminum or steel. Atop these disks is another is another small disk to which is attached a hanging mass. In this experiment, the hanging mass, the radius of the disk which holds the hanging mass, and the material of the two disks will be changed. This will be done to determine if these factors could affect angular acceleration.
Here is a picture of our actual set up:

Procedure:

The first thing to do is to gather the necessary data for the lab. This includes the diameter and mass of the top steel disk, the diameter and mass of the bottom steel disk, the diameter and mass of the top aluminum disk, the diameter and mass of the smaller torque pulley, the diameter and mass of the larger torque pulley, and the mass of the hanging mass.

This data can be seen below:

We then cleaned the disks with alcohol to try to prevent friction as they rotate. We then adjusted our data collection equipment so that it only read the rotation of the top disk and read 200 counts per rotation. We made sure the hose clamp on the bottom was open so that the top disk would rotate independently of the bottom disk.  We then turned on the compressed air and set the disks spinning freely. Lastly, we started measurements by releasing the mass at its highest point.

Results:
From our data collection we were able to create graphs of angular velocity and use those to determine the angular acceleration as the mass moves up and down. In total there were 6 experiments:

Expt 1: 

hanging mass= 10 g

Small torque Pulley

Top Disk- steel

Expt 2: same conditions as Expt 1 except hanging mass = 20 g

Expt 3: Same condtions as Expt 1 except hanging mass now = 30 g

Expt 4: Same conditions as Expt 1 except now large torque pulley was used

Expt 5: Same conditions as Expt 4 except now the top disk will be of aluminum

Expt 6: Same conditions as Expt 4 except now the both the top and bottom disks will be of steel

From all the angular accelerations have been organized in the table below:

Conclusions:
From our data, it can be concluded that certain factors can indeed affect angular acceleration. Increasing the mass tends to increase the angular acceleration. Also, the radius of the larger pulley was more than twice the smaller torque pulley. And when using the larger torque pulley it can be seen that the acceleration also doubled. Furthermore, the aluminum disk had about 1/3 the mass of the steel disk. And when the aluminum disk was used the angular acceleration increased by about 1/3 more than when using the steel disk. So in conclusion, angular acceleration is fastest when using lighter disks, larger torque pulleys and more mass,