Here is the ectra info if needed: Procedure 1 Use the same method you used last
ID: 1519811 • Letter: H
Question
Here is the ectra info if needed:
Procedure 1
Use the same method you used last week to find the moment of inertia of the system (with nothing on it): • Wrap the string around the smallest wheel on the 3 step pulley. • Put the mass hanger (with no masses on it) on the end of the string. • Release the mass, and click on Record. As the mass hanger hits the ground, click on Stop. • Highlinght the area of the graph before the mass hanger hit the ground. Use a linear fit to find , the magnitude of the angular acceleration. • Now, calculate a, the magnitude of the acceleration of the falling mass, T, the tension in the string, , the torque on the sysem, and I, the moment of inertia of the system. • Record these values on your data sheet. You will use this value as the moment of inertia of the system in later calculations.
Explanation / Answer
Let I1 be the moment of inertia of disk
Mass of disk is m = 908 g = 0.908 kg
Since there is no external torque on the system, angular momentum conserved.
Total initial angular momentum = Total final angular momentum
I*o = (I + I1)f
I*o = If + I1f
I1 = I (o - f) / f
I1 = 2.57* (5.63 - 4.24) / 4.24
I1 = 0.8425 kg.m2
But the moment of inetia of disk is I1 = (1/2)mr2
0.8425 kg.m2 = (1/2)(0.908 kg)r2
r = 1.36 m