JEE Main202315 Apr 2023Morning ShiftPhysicsWork, Power and EnergyActual
A body is released from a height equal to the radius R of the earth. The velocity of the body when it strikes the surface of the earth will be: (Given g = acceleration due to gravity on the earth.)
Options
- A2 g R
- Bg R
- C4 g R
- Dg R 2
Correct answer
B. g R
Step-by-step solution
Using conservation of mechanical energy, U i + K i = U f + K f ⇒ - G M m 2 R + 0 = - G M m R + 1 2 m v 2 ⇒ 1 2 m v 2 = G M m 2 R ⇒ v = GM R = g R