A particle goes round a circular path with uniform velocity v. After describing half the circle, the average acceleration of the particle (if its radius is r) is :

Options

A. `(v^(2))/(r )`
B. `(2v^(2))/(r )`
C. `(v^(2))/(pir )`
D. `(2v^(2))/(pir )`

Answer

D

Explanation

Here, change in velocity after half revoution =v-(-v)=2v. Time taken in describing half circle =`(pir)/(v)`, `therefore` `a=(2v)/(pir)xxv=(2v^(2))/(pir)`.