JEE Main Physics question
A 3 kg body is dropped from the top of a tower of height 135 m. If g = 10 ms⁻², then the kinetic energy of the body after 3 s will be
Answer: (D)
Solution
v = gt = 10×3 = 30 ms⁻¹ (the body hasn't hit the ground yet, since full fall time is √(2×135/10)≈5.2s). KE = ½(3)(30²) = 1350 J.