A solid disk starts from rest and experiences a constant angular acceleration of for…

PHYSICS · Single correct · A Level · Physics · Engineering physics · Engineering physics

Problem

A solid disk starts from rest and experiences a constant angular acceleration of

3.0\,\text{rad/s}^2

for the first

4.0\,\text{s}

. The net torque is then removed, and the disk continues to rotate without friction for an additional

3.0\,\text{s}

. What is the disk’s angular velocity after the full

7.0\,\text{s}

? (a)

21\,\text{rad/s}

(b)

0\,\text{rad/s}

(c)

12\,\text{rad/s}

(d)

6\,\text{rad/s}