Question

A wheel is at rest. Its angular velocity increases uniformly and becomes 60 rad/sec after 5 sec. The total angular displacement is

• A. $600rad$
• B. $75rad$
• C. $300rad$
• D. $150rad$

Answer 1

Answer: (D)

$150rad$

Answer 2

Angular acceleration

$\alpha = \frac{\omega_{2} - \omega_{1}}{t} = \frac{60 - 0}{5} = 12rad/sec^{2}$

Now from $\theta = \omega_{1}t + \frac{1}{2}\alpha t^{2}$= $0 + \frac{1}{2}(12)(5)^{2} = 150rad.$