Question

A force of 45 N is applied tangentially to the rim of a solid disk of radius 0.12 m. The disk rotates about an axis through its center and perpendicular to its face with a constant angular acceleration of 140 rad/s2. Determine the mass of the disk.

Answer 1

Mass of the disk will be 2.976 kg

Step-by-step explanation:

We have given force F = 45 N

Radius of the disk r = 0.12 m

Angular acceleration
`\alpha =140rad/sec^2`

We know that torque
`\tau =I\alpha`

And
`\tau =Fr`

So
`Fr=I\alpha` , here I is moment of inertia

So
`50* 0.12=I* 140`

`I=0.0428kgm^2`

We know that moment of inertia
`I=(1)/(2)mr^2`

So
`0.0428=(1)/(2)* m* 0.12^2`

m = 2.976 kg