Lab: angular acceleration

Lab: angular acceleration

Purpose:

Using different  mass of the top disk, different hanging mass and different torque pulley to see what factors affect the angular acceleration.

Apparatus:

The diameter and mass of the top steel disk: 126.6mm      1356g

The diameter and mass of the bottom steel disk: 126.6mm      1348g

The diameter and mass of the top aluminum disk: 126.6mm      466g

The diameter and mass of the small torque pulley: 12.5mm      10.0g

The diameter and mass of the large torque pulley: 25.0mm      37.0g

The mass of the hanging mass supplied with apparatus: 

Experiment:

1. Set up the apparatus as the pictures show.

2. Set up the Pasco rotational sensor and computer, set the equation on the sensor setting to 200 counts per rotation.

3. Make sure the hose clamp on the bottom is open so that the bottom disk will rotate independently of the top disk when the drop pin is in place.

4. Turn on the compressed air so that the disks can rotate separately.

5. Wrap the string around the torque pulley to the highest point, start measurements and release the mass. 

6. Use the graph of angular velocity vs. time to measure the angular acceleration of upward motion and downward motion.

7. Follow the instruction and change the factors to get angular acceleration under each condition.

Result:

Conclusion:
EXPTS 1,2, and 3: Effect of changing the hanging mass----the heavier the hanging mass, the larger the angular accerleration
EXPTS 1 and 4: Effect of changing the radius and which the hanging mass exerts a torque----The larger the radius, the larger the angular acceleration.
EXPTS 4,5, and 6: Effect of changing the rotating mass----the lighter the rotating mass, the larger the angular acceleration.