State the law of conservation of energy.

The potential energy of a freely falling object decreases progressively. Does this violate the law of conservation of energy? Why?

$A$ freely falling object eventually stops on reaching the ground. What happens to its kinetic energy?

$A$ battery lights a bulb. Describe the energy changes involved in the process.

$(a)$ Name two forms of energy involved while a pendulum oscillates.
$(b)$ Show with the help of a diagram that when does each type of energy attain its maximum value.
$(c)$ How do these energies vary while the pendulum oscillates?
$(d)$ Name and state the law involved.

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.