An athlete throws a discus from rest to a final angular velocity of 15 rad `s^(-1)` in 0.270 s before releasing it. During acceleration, discus moves in a circular arc of radius 0.810 m. Acceleration of discus before it is released is

Options

A. `45 m s^(-2)`
B. `182 m s^(-2)`
C. `187 m s^(-2)`
D. `192 m s ^(-2)`

Answer

A

Explanation

`omega = omega_(0) + alpha t or omega = 0 + alpha t`
or `alpha = (omega)/(t) = (15)/(0.270) rad s^(-2)`
`therefore a = r alpha = 0.81 xx (15)/(0.270) = 45 ms^(-2)`