Question

Two constant horizontal forces $F_1$ and $F_2$ are acting on blocks A and B. At an instant acceleration of block B is 4 $m/s^2$ in direction of $F_1$ and acceleration of block A with respect to block B at this moment is :

All the surfaces are smooth.

• A. 1 $m/s^2$
• B. 2 $m/s^2$
• C. 5 $m/s^2$
• D. 9 $m/s^2$

Answer 1

The correct option is A 1 $m/s^2$

Net force $=100-70=30N$
Also, Net force $=5\times 4+2a=30$
Or, $a=5m/s^2$
Therefore acceleration of A w.r.t B $=1m/s^2$