Question

A wheel is rotating in a circular motion with the angular speed of 3600 revolution per minute (rpm). What will be its speed in radian/sec?
1. 60π rad/sec
2. 120π rad/sec
3. 100π rad/sec
4. 30π rad/sec

Answer 1

Correct Answer - Option 2 : 120π rad/sec

CONCEPT:

• Angular velocity (ω): How fast the angular orientation or position of an object changes with time is called angular velocity. 
  • How fast an object rotates or revolves relative to another point is known as angular velocity.
    • Angular velocity in terms of RPM (revolutions per minute) 

ω = 2πf/60

where f is in revolution per minute and ω is in terms of radian per second.

CALCULATION:

Given that f = 3600 rpm; 

ω = 2πf/60 = (2π × 3600)/60 = 120π rad/sec

So the correct answer is option 2.