Question

In the figure, a force $F=20N$ is applied on block $A$. What would be the acceleration of the block $B$ after $10$ seconds from the start? (Assume all surfaces are smooth).

• A. $10/6m/s^2$
• B. $2m/s^2$
• C. zero
• D. cannot be calculated

Answer 1

The correct option is C zero

Since the contact force between $A$ and $B$ is the normal reaction which is vertical, no horizontal force acts on $B$. Hence its $a_B=0$