Question

A ball is thrown upwards from a point $A$. It reaches up to the highest point $B$ and returns, then-
$[$Assume space to be vacuum$]$

• 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

The correct option is D Potential energy at $B=$ Kinetic energy at $A$


From Law of Conservation of Mechanical Energy,

$P{E}_A+K{E}_A=P{E}_B+K{E}_B$

$\Rightarrow 0+K{E}_A=P{E}_B+0$

$\Rightarrow K{E}_A=P{E}_B$