A flywheel with moment of inertia rotates at counter-clockwise

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

Problem

A flywheel with moment of inertia

5.0\,\text{kg}\cdot\text{m}^2

rotates at

20\,\text{rad}\,/\text{s}

counter-clockwise. It first experiences a constant clockwise torque of

10\,\text{N}\cdot\text{m}

for

2.0\,\text{s}

. Immediately afterward, a constant counter-clockwise torque of

6.0\,\text{N}\cdot\text{m}

acts for

4.0\,\text{s}

. What is the flywheel’s angular speed after the second torque ends? (a)

20.4\,\text{rad/s}

counter-clockwise (b)

28.8\,\text{rad/s}

counter-clockwise (c)

20.8\,\text{rad/s}

counter-clockwise (d)

15.2\,\text{rad/s}

counter-clockwise