Question

A torque of 15Nm is applied to a heavy wheel whose moment of inertia is 40 kgm2. What is the angular acceleration of the wheel? If the wheel was initially at rest and the torque is applied for 15 s, what will be the rotational frequency ω of the wheel at the end of the 15 s?

Answer 1

(a) Applied torque, = 15 N*m

Moment of inertia of the wheel, I = 40 kg*m^2

Angular acceleration of the wheel, = ?

Write down the expression -

= I *

=> = / I = 15 / 40 = 0.375 rad/s^2 (Answer)

(b) Torque is applied for a time, t = 15 s

Initial rotational frequency, = 0

Final rotational frequency, = ?

Use the expression -

= + * t

= 0 + 0.375 * 15 = 5.625 rad/s (Answer)