$A$ weightlifter lifts $240 \,kg$ from the ground to a height of $2.5 \,m$ in $3 \,s$. The average power is:

$(a)$ What is meant by potential energy? Is potential energy a vector or scalar quantity?
$(b)$ Give one example of a body having potential energy.

$A$ light and a heavy body have the same momentum. Which one will have greater kinetic energy?

An object of mass $10 \ kg$ is made to fall freely from a height of $10 \ m$. Complete the table:

Height of object $(m)$	$PE$ $(J)$	$KE$ $(J)$	Mechanical Energy $(J)$
$10$	...	...	...
$8$	...	...	...
$5$	...	...	...
Just above ground	...	...	...

Hence,state the law of conservation of energy.

$(a)$ Two bodies have equal masses and are moving with uniform velocities of $2\,v$ and $3\,v$. What is the ratio of their kinetic energies?
$(b)$ $A$ mass is dropped from height $h$. At halfway to the ground,what is the total energy?

$A$ light and a heavy object have the same momentum. Find the ratio of their kinetic energies. Which one has a larger kinetic energy?