JEE Main Physics question
A stone of mass 2 kg is projected upward with KE of 98 J. The height at which the KE of the body becomes half its original value is given by (g = 10 ms⁻²)
Answer: (B)
Solution
PE gained at height h equals half the initial KE lost: mgh = 49 J ⟹ 2(10)h = 49 ⟹ h = 2.45 m ≈ 2.5 m.