Two blocks of masses of `0.2 kg` and `0.5 kg` which are placed `22m` apart on a horizontal surface `(mu = 0.5)` are acted upon by two forces of magnitude `3 N` each as shown in figure in time `t = 0` Then the time t at which they collide with each other is

Options

A. `1s`
B. `sqrt(2)s`
C. `2s`
D. None

Answer

C

Explanation

`a_(1) = (F - f_(1))/(m_(1)) = (F - mu m_(1)g)/(m_(1)) = 10 ms^(-2)`
`a_(2) = (F - mu m_(2) g)/(m_(2)) = 1 ms^(-2)`
`:. S = (1)/(2) a_(real)t^(2 ) = (1)/(2) (10 + 1)1^(2) rArr t = 2s`