Question

A ball is thrown up at an angle with the horizontal. Then the total change of momentum by the instant it returns to ground is

• A. acceleration due to gravity $ \times $ total time of flight
• B. weight of the ball $ \times $ half the time of flight
• C. weight of the ball $ \times $ total time of flight
• D. weight of the ball $ \times $ horizontal range

Answer 1

Answer: (C)

Change in momentum of the ball
$=m v \sin \theta-(-m v \sin \theta)=2 m v \sin \theta$
$=m g \times \frac{2 \nu \sin \theta}{g}$
$=$ weight of the ball $\times$ total time of flight