A ball of mass 30kg thrown from a ground,it follows a parabolic path again 10m away from its original position,calculate the work done.
Answers
The correct answer to the question is zero.
CALCULATION:
The mass of the ball m = 30 kg.
The ball is thrown from the ground and the path traversed by the ball is parabolic in nature.
The only force that acts on the ball is gravitational force.
Hence, the work done by the body is due to the gravitational force.
When the ball is fired making an angle with the horizontal, the ball goes up and reaches its maximum height. The ball falls downward after reaching the maximum height.
The work done by the ball is equal to the potential energy gained by the body .
Let the maximum height is h.
Hence, the work done by the by the ball moving up = -mgh.
The work done by the when it reaches at the ground = + mgh.
The work done by the ball while moving up is equal to the work done by the ball while moving down.
Hence, the upward work will cancel the downward work. So, the net work done by the ball is zero.