Question

A force of 40 N is applied tangentially to the rim of a solid disk of radius 0.10 m. The disk rotates about an axis through its center and perpendicular to its face with a constant angular acceleration of 145 rad/s2. Determine the mass of the disk.

Answer 1

m = 2,759 kg

Step-by-step explanation:

For this exercise we use the torque relationship

τ = I α

the moment is

τ= F r sin θ

since the force is tangential to the ring, the angle is 90º sin 90 = 1

τ = F r

the moment of inertia of a ring is given by

I = m r²

let's substitute

F r = m r²α

m = F / r α

let's calculate

m = 40 / (0.10 145)

m = 2,759 kg