A `10 kg` block is placed on top of a `40 kg` block as shown in figure .A horizontal force F acting on B cause an acceleration of `2 ms^(-2)` to B .For this situation marks our the correct statement(s)

Options

A. The acceleration of A may be `2 ms^(-2)` or less than `2 ms^(-2)`
B. The acceleration of A mass also be `2 ms^(-2)`
C. The coefficient of friction between the blocks may be `0.2`
D. The coefficient of friction between the blocks must be `0.2` only

Answer

b,c

Explanation

`F = 10a_(1) + 40a_(2)`
`rArr 100 = 10a_(1)+ 40 xx 2`
`rArr a_(1) = 2 ms^(-2)`
So acceleration of A be `2 ms^(-2)` for given conditions to be satisfied

`f = 10a_(1) = 10 xx 2 = 20 N`
`f le f_(1) rArr 20 le mu m_(A)g`
`rArr 20le mu xx 10g rArr mu ge 0.2`
Hence m can be greater or equal to `0.2`