If the velocity v of particle moving along a straight line decreases linearly with its displacement s from `20 ms^(-1)` to a value approaching zero at s = 30 m, then acceleration of the particle at v=10ms^(-1)` is

Options

A. `(2)/(3)ms^(-2)`
B. `-(2)/(3)ms^(-2)`
C. `(20)/(3)ms^(-2)`
D. `-(20)/(3)ms^(-2)`

Answer

D

Explanation

`a=upsilon((d upsilon)/(ds))=(10)(-(20)/(30))=-(20)/(3)ms^(-2)`