Question

A ball, when kept on a spring attains a certain height after it is compressed and released. For which of the following height attained by the ball, maximum of his energy is required to compress the spring?

• A. $3m$
• B. $5m$
• C. $7m$
• D. $9m$

Answer 1

The correct option is D $9m$

Maximum energy depends on the work done in compressing the spring which is directly proportional to the height attained by the ball after the spring is released. The gravitational potential energy is expressed as "m x g x h” and it would be the maximum for the height of $9m$. So, he has to do maximum work to compress the spring when the ball rises to a height of $9m$.