Question

The angular speed of the second's hand of a watch is:
1. 1 rad/s
2. 60 rad/s
3. π rad/s
4. π/30 rad/s

Answer 1

Correct Answer - Option 4 : π/30 rad/s

CONCEPT:

• Angular velocity (ω): It is defined as the rate of change of angular displacement (θ).

∴ω = θ / t

Hence, a unit of angular velocity in rad/sec or degree/sec

CALCULATION:

Given that:

Second-hand clock:

Time taken to complete 1 revolution, t = 60 sec

Angle rotated (θ) = 2π rad

Angular speed (ω) of a second hand is given by:

 \(\left( {{ω }_{s}} \right)=\frac{2π }{60}= \frac{\pi }{30} \) rad/s

So option 4 is correct.