A body of mass 40kg resting on a rough horizontal surface is subjected to a force `P` which is just enough to start the motion of the body. If `mu_(s)=0.5mu_(k)=0.4 , g=10ms^(-2)` an dthe force `P` is continuously applied on the body, then the accceleration of the body is.

Options

A. zero
B. `1 ms^(-2)`
C. `2 ms^(-2)`
D. `2.4 ms^(-2)`

Answer

B

Explanation

(b) Force, `P=f_(m)=mu_(0) mg`(when body is rest)
When the body starts moving with acceleration a, then `P-F_(k)=ma`
`mu_(0) mg-mu _(k) mg =ma`
`a=(mu_(0)=mu_(k))g`
=(0.5-0.4)10
`=0.1xx10ms^(-2)=1 ms^(-2)`