Physics - W.E.P. Question with Solution | TestHub

Initial kinetic energy is$490\text{J}$

Let h be the height at which kinetic energy becomes half of the initial value

$\frac{KE}{2}=\frac{490}{2}=245\text{J}$

Gain in Potential energy at height h is mgh

This is equal change in kinetic energy

$\Delta KE=490\text{J}-245\text{J}=245\text{J}$

$mgh=245\text{J}$

$h=\frac{245}{2\times 9.8}=12.5\text{m}$