Question

A force F is applied horizontally to a block A of mass $m_1$ which is in contact with a block B of mass $m_2$, as shown in the figure. If the surfaces are frictionless, the force exerted by A on B is equal to

• A. $\frac{m_{1}F}{m_2}$
• B. $\frac{m_{2}F}{m_1}$
• C. $\frac{m_{1}F}{m_1+m_2}$
• D. $\frac{m_{2}F}{m_1+m_2}$

Answer 1

The correct option is D

$\frac{m_{2}F}{m_1+m_2}$

Acceleration of the system, $a=\frac{F}{m_1+m_2}$
Now, the force exerted by A on B is responsible for the acceleration of block B and is given by $F^{\prime }=m_{2}a=\frac{m_{2}F}{m_1+m_2}$.
Hence, the correct choice is (d).