A particle moves along a circle if radius `(20 //pi) m` with constant tangential acceleration. If the velocity of the particle is ` 80 m//s` at the end of the second revolution after motion has begun the tangential acceleration is .

Options

A. `1.6`
B. `4`
C. `15.6`
D. `13.2`

Answer

C

Explanation

Given `r=20/pi m`
Angular velocity after second revolution
`omega=v/r=(50pi)/20=(5pi)/2`
`omega_("final")^(2)=omega_("initial")^(2)+2alpha theta`
`25/4 pi^(2)=2alpha(4pi) rArr alpha=(25 pi)/32`
`a_(t)=alphar=(25pi)/32xx20/pi=15.6`