A mass of `5kg` is moving along a circular path or radius `1m`. If the mass moves with 300 revolutions per minute, its kinetic energy would be

Options

A. `250 pi^2`
B. `100 pi^2`
C. `5 pi^2`
D. 0

Answer

A

Explanation

Given, mass = m = 5 kg
Radius = 1m = R
Revolution per minute,
`omega = 300 rev`/ min `= (300 xx 2pi) ` rad/min
`implies (300 xx2 xx3.14) rad //60 s = (300xx2 xx3.14)/(60) rad//s`
`=10 pi` rad/s
Linear speed `= v = omegaR`
`=((300 xx2pi)/60) (1) = 10 pim//s`
KE `=1/2mv^2`
`=1/2 xx 5 xx (10pi)^2 = 100 pi^2 xx 5 xx1/2`
`= 250 pi^2 J`