Question

A ball is dropped from a height of 10 m. If the energy of the ball reduces by 40% after striking the ground, how much high can the ball bounce back?

• A. 6 m
• B. 4 m
• C. 3 m
• D. None of the above

Answer 1

The correct option is A 6 m

Total energy of the ball = m g h
$=mg10$
$=100mkg{m}^2{s}^{-2}$
Energy with which it moves up the ground after striking= 60% of the total energy
$E=\frac{60}{100}\times 100mkg{m}^2{s}^{-2}$
Height to which the ball will bounce back
$h=\frac{E}{m\times g}=6$ meter