Question

In 20sec A motor changes it's velocity from 1200 rpm to 1800rpm. In this period, the no. of rotations made by it

Answer 1

Answer:

500

Explanation:

Given,

ω0=1200rpm=20rps

ω=1800rpm=30rps

t=20sec

From the rotational mechanics

ω=ω0+αt

α=tω−ω0 

α=2030−20=0.5rps2

The number of rotation,

θ=ω0t+21αt2

θ=20×20+21×0.5×20×20

θ=400+100=500rotation