A 1 kg object strikes a wall with velocity 1 m s$^{-1}$ at an angle of $60^\circ$ with the wall and reflects at the same angle. If it remains in contact with wall for 0.1 s, then the force exerted on the wall is:-

A $30\sqrt3$ N

B Zero

C $10\sqrt3$ N

D $20\sqrt3$ N

The answer is C.

Solution

$F=\left|\dfrac{\Delta\vec p}{\Delta t}\right|=\dfrac{2mv\sin\theta}{t}=\dfrac{2(1)(1)\sin60^\circ}{0.1}=10\sqrt3$ N.

Concept Impulse-momentum theorem - collision with a wall

72 questions from this chapter have appeared across 27 exam years.