STANDARDPhysics-Laws of Motion
STANDARD Physics Impulse and Momentum MCQ Question
Type: MCQ-conceptual-Medium-Class 11
A ball of mass m strikes a rigid wall with speed u at an angle of 30° and gets reflected with the same speed and at the same angle as shown in the figure. If the ball is in contact with the wall for time t, then the force acting on the wall is
A
mu sin30° / t
B
2mu sin30° / t
C
mu cos30° / t
D
2mu cos30° / t
Correct Answer
Option D
Detailed Explanation
The initial momentum of the ball is mu cos30° i - mu sin30° j. The final momentum is -mu cos30° i - mu sin30° j. The change in momentum is -2mu cos30° i. Using Newton's 3rd law, the force on the wall is 2mu cos30° / t.
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