Question

A rigid ball of mass $m$ strikes a rigid wall at ${60}^{\circ }$ and gets reflected without loss of speed as shown in the figure. The value of impulse imparted by the wall on the ball will be

• A. $mV$
• B. $2mV$
• C. $\frac{mV}{2}$
• D. $\frac{mV}{3}$

Answer 1

The correct option is A $mV$

$\text{Impulse}=\text{Force}\times \text{time}=\text{Change in momentum}$

i.e $Ft=mv-mu$


Change in momentum along x direction $=2mVcos60=mV$

Change in momentum along y direction $=0$

$\therefore \text{Impulse}=\text{Net change in momentum}=mV$