Block `A` of mass `2kg` is placed over a block `B` of mass `8kg` . The combination is placed on a rough horizontal surface. If `g=10ms^(-2)` , coefficient of friction between `B` and floor `=0.5` , coefficient of friction between `B` and floor `=0.5` , coefficient of friction between `A` and `B=0.4` and a horizontal force of `10N` is applied on `8kg` block, then the force of friction between `A` and `B` is.

Options

A. zero
B. 50 N
C. 80 N
D. 10 N

Answer

A

Explanation

`f_(1) le 8N` `:.` `f_(1) =0 N, f_(2) = 10 N`
`f_(2) le 50 N`