NDA2025General AbilityGeneral ScienceActual
Suppose, a ball of mass M is thrown upwards from a point A and it reaches up to the highest point B and returns back to point A, which one among the following is correct?
Options
- AKinetic Energy at A = Potential Energy at B
- BKinetic Energy at A = Potential Energy at A
- CKinetic Energy at B = Potential Energy at B
- DKinetic Energy at B = Kinetic Energy at A
Correct answer
A. Kinetic Energy at A = Potential Energy at B
Step-by-step solution
Let the reference level for potential energy be at point A. Thus, the potential energy at A is zero. When the ball is thrown upwards from point A with velocity v , its kinetic energy is 1 2 Mv^2 . Total mechanical energy at A is E_A = 1 2 Mv^2 + 0 = 1 2 Mv^2 . At the highest point B, the velocity of the ball becomes zero, so its kinetic energy at B is zero. Let the height of point B from A be h . The potential energy at B is Mgh . Total mechanical energy at B is E_B = 0 + Mgh = Mgh . According to the law of conserv