A mass of 2 kg is placed on a trolley of 20 kg sliding on a smooth surface. The coefficient of friction betwe! the mass and surface of trolley is 0.25. A horizontal force of 2N is applied to the mass. The acceleration of system and the frictional force between the mass and surface of trolley are

Options

A. `1.8 ms^-2, 0.09 N`
B. `0.9 ms^-2, 18N`
C. `0.09 ms^-2, 1.8 N`
D. `1 ms^-1, 2N`

Answer

C

Explanation

Limiting frictional force `=mu mg =0.25 xx 2 xx 10 =5 N`
The block and trolley will not have relative motion for a force of 2N
`2=(20+2)a`
`a=2/22=1/11=0.09 ms^-2" ":. F=20 xx 0.09=1.8 N`