A boy while playing wanted to throw a ball of mass 200g atop such that it could reach his friend, who is standing at a height of 5m from ground. Frustrated with repetitive failures, he managed to find a spring and compressed it to develop certain potential energy so that ball could reach his friend. Estimate the work done by the boy such that the ball just reaches his friend (take 'g' = 10 m/s2).
A boy while playing wanted to throw a ball of mass 200g atop such that it could reach his friend, who is standing at a height of 5m from ground. Frustrated with repetitive failures, he managed to find a spring and compressed it to develop certain potential energy so that ball could reach his friend. Estimate the work done by the boy such that the ball just reaches his friend (take 'g' = 10 m/s2).
The correct option is C 10 J
The minimum work done by the boy on the spring should be such that it develops necessary potential energy for the ball to reach at a height of 5m. So, the gain in gravitational potential energy of the ball or the work done against gravity would be the work done by the boy such that the ball reaches his friend. So, gain in gravitational potential energy = m x g x h,
200/1000 x 10 x 5 = 10 J.
10 J
The minimum work done by the boy on the spring should be such that it develops necessary potential energy for the ball to reach at a height of 5m. So, the gain in gravitational potential energy of the ball or the work done against gravity would be the work done by the boy such that the ball reaches his friend. So, gain in gravitational potential energy = m x g x h,
200/1000 x 10 x 5 = 10 J.
