Two constant horizontal force `F_1` and `F_2` are acting on blocks A and B. At an instant acceleration of block B is `4m//s^2` in direction of `F_1` and acceleration of block A w.r.t block B at this moment is:

Options

A. `1 m//s^(2)`
B. `2 m//s^(2)`
C. `7 m//s^(2)`
D. `9 m//s^(2)`

Answer

A

Explanation

`F_("net")=m_(1)a_(1)+m_(2)a_(2)rArr 100-70=5xx4+2xxarArr a=5m//s^(2)`
So, `a_("rel")=5-4 =1 m//s^(2)`