NDA 2 2024 GAT, question 97

Topic: Physics

Q97

There is a ball of mass $320\text{ g}$ . It has $625\text{ J}$ potential energy when released freely from a height. The speed with which it will hit the ground is

(a) $62.5\text{ m/s}$ Correct answer
(b) $2.0\text{ m/s}$
(c) $50\text{ m/s}$
(d) $40\text{ m/s}$

Solution.

Answer: (a) $62.5\text{ m/s}$

Use kinetic energy E=mv²/2.
With E=625 J and m=0.32 kg, v²=2×625/0.32=3906.25, so v=62.5 m s⁻¹.
This uses the stated mechanical-energy model without an additional loss term.