Question

The angular speed of the wheel of a vehicle is increased from 360 rpm to 1200 rpm in 14 second. Its angular acceleration is :

(1) 1 rad/s²

(2) 2π rad/s²

(3) 28π rad/s²

(4) 120π rad/s²

Answer 1

Use the eqn w=w0t+1/2at2

1200/60*2pi=40pi. 360/60*2pi=10pi.  

Substitute theta =140pi+15/7pi*14*14=560pi

Implies 2pin=560pi

n=280

No of revolution =280

Comments

Read question first and what your solution both are totally different.