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 p^(2)`
B. `100 p^(2)`
C. `5 p^(2)`
D. 0

Answer

A

Explanation

Given, mass `= m = 5kg`
Radius `= 1 m = R`
Revolution per minute
`omega =300 rev//min`
=`(300 xx 2pi)rad//min`
=`(300 xx 2xx3.14) rad//60s`
=`(300 xx 2 xx 3.14)/(60) rad//s = 10 pi rad//s`
`rArr "Linear speed" = v = omega R`
`=((300 xx 2 pi)/(60)) (1)`
`=10 pi m//s`
`KE = (1)/(2) mv^(2)`
`=(1)/(2) xx 5 xx(10 pi)^(2)`
`=100 pi^(2) xx 5 xx (1)/(2)`
=`250 pi^(2) J`.