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

Answer:

 m = 2,759 kg

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