A 60kg body is pushed with just enough force to start it moving across a floor and the same force continues to act afterwards. The coefficients of static and sliding friction are 0.5 and 0.4 respectively. The acceleration of the body is

Options

A. `6m//sec^(2)`
B. `4.9 m//sec^(2)`
C. `3.92 m//sec^(2)`
D. `0.98 m//sec^(2)`

Answer

D

Explanation

`F_(f)= mu N`
`F= 0.5 xx 60 xx 9.8 = 294N` (static)
`F= 0.4 xx 60 xx 9.8 = 235.2N` (kinetic)
`a= (F)/(m)= (58.8)/(60)= 0.98m//s^(2)`