Question

Find the angular acceleration of a particle in circular motion which slows down from 300 r.p.m. to 0 r.p.m. in 20 s.

Answer 1

Given: n₁ = 300 rpm

`n_1=300/60= 5  rps=5  Hz`

`n_2=0, t=20s`

Angular acceleration,

`alpha=(omega_2-omega_1)/t`

`alpha=(2pin_2-2pin_1)/20`

`alpha=(0-2pixx5)/20=(-pi)/2` rad/s²

`alpha=(-3.14)/2` rad/s²

`alpha = -1.57` rad/s²