Question

A smooth block of mass m is placed on a smooth plank of mass M. The acceleration of M when it is acted by a force F is? Also find acceleration of m?

• A. $a_M=\frac{F}{M+m};a_m=\frac{F}{M+m}$
• B. $a_M=\frac{F}{M+m};a_m=zero$
• C. $a_M=zero;a_m=zero$
• D. $a_M=\frac{F}{M};a_m=zero$

Answer 1

The correct option is D

$a_M=\frac{F}{M};a_m=zero$

Free Body Diagram of m & M are

From Free Body Diagram of M:F = M.A

$A=\frac{F}{M}$

From Free Body Diagram of m: it is clear,acceleration a = 0