Question

The length of the second’s hand of a watch is 10 mm. What is the change in the angular speed of the watch after 15 seconds

• A. Zero
• B. $(10\pi/2)mms^{- 1}$
• C. $(20/\pi)mms^{- 1}$
• D. $10\sqrt{2}mms^{- 1}$

Answer 1

Answer: (A)

Zero

Answer 2

Angular speed of seconds hand of watch is constant and equal to $\frac{2\pi}{60}\frac{rad}{\sec} = \frac{\pi}{30}rad/sec$. So change in angular speed will be zero.