question_answer

100 g of a iron ball having velocity 10 m/s collides with a wall at an angle \[{{30}^{o}}\] and rebounds with the same angle. If the period of contact between the ball and wall is 0.1 second, then the force experienced by the ball is [DPMT 2000]

A)          100N                             

B)          10 N

C)          0.1 N                             

D)          1.0 N

Correct Answer: B

Solution :

         F = Rate of change in momentum               \[=\frac{2mv\sin \theta }{t}\]               \[=\frac{2\times {{10}^{-1}}\times 10\sin 30{}^\circ }{0.1}\]               \\[F=10\,N\]