Question

A body of mass $M$ hits normally a rigid wall with velocity $V$ and bounces back with the same velocity. The impulse experienced by the body is

• A. MV
• B. 1.5 MV
• C. 2 MV
• D. zero

Answer 1

Answer: (C)

2 MV

Answer 2

A Body of mass $=m$
velocity $=V(\hat{i})$
Knock out (Bounce velocity) $=V(-\hat{i})$
Change in momentum $=m(v)-(m)(-v)$
$=2 M V$
Rate of change of momentum is Force
Thus $\frac{d \vec{p}}{d t}=$ force.
force $\times$ time $=$ Impulse
Thus Impulse Experience by body $=2 m v .$