Question

A ball is thrown upwards from point A. It reaches up to point B and returns. What can be concluded?

• A. Kinetic energy at A = kinetic energy at B
• B. Potential energy at A = potential energy at B
• C. Potential energy at B = kinetic energy at B
• D. Potential energy at B = kinetic energy at A

Answer 1

Answer: (D)

Potential energy at B = kinetic energy at A

AT point A the body has kinetic energy only while at B it has potential energy only.

From work-energy theorem:

$K_B-K_A=V_A-V_B$

$0-K_A=0-V_B$

Kinetic energy at A=potential energy at B