Posted by **Oscar** on Monday, October 25, 2010 at 6:13pm.

A disk with a mass of 18 kg, a diameter of 50 cm, and a thickness of 8 cm is mounted on a rough horizontal axle as shown on the left in the figure. (There is a friction force between the axle and the disk.) The disk is initially at rest. A constant force, F = 70 N,is applied to the edge of the disk at an angle of 37°, as shown on the right in the figure. After 2.0 s, the force is reduced to F = 27 N,and the disk spins with a constant angular velocity.

What is the angular velocity after 2 sec?

- Angular Velocity Question -
**bobpursley**, Monday, October 25, 2010 at 6:21pm
Figure moment of inertia I for the disk.

wi=0

Torque= I*angacceleration

70*.25*trigfunction= I acceleration

I dont understand the figure, so you will need to account for the angle. It is probably cos 37

find acceleration.

then

wf=wi+I acceleration*time

figure wf at time=2

Now, after two sec, figure the new angular acceleration. wi now is w at 2 seconds

wf(t)=w(2)i + I newacclearation *t

and you get a function of time.

- Angular Velocity Question -
**Oscar**, Monday, October 25, 2010 at 7:27pm
I'm not getting the correct answer this way. Maybe I'm doing something wrong.

## Answer this Question

## Related Questions

- Physics - A disk with a mass of 13 kg, a diameter of 25 cm, and a thickness of 8...
- Physics - A disk with a mass of 18 kg, a diameter of 50 cm, and a thickness of 8...
- Calc Physics - A disk with a mass of 17 kg, a diameter of 25 cm, and a thickness...
- Physics - A rotating uniform-density disk of radius 0.7 m is mounted in the ...
- Physics Classical Mechanics - A solid disk 1 with radius R1 is spinning freely ...
- Physics - A rotating uniform-density disk of radius 0.6 m is mounted in the ...
- Physics - A solid cylindrical disk has a radius of 0.18 m. It is mounted to an ...
- physics - A solid cylindrical disk has a radius of 0.17 m. It is mounted to an ...
- physics - A solid cylindrical disk has a radius of 0.16 m. It is mounted to an ...
- Physics (help) - A solid disk 1 with radius R1 is spinning freely about a ...