Law of Conservation of Energy

A ball falls to the ground as shown below:

 What is the potential energy of ball at B? State the law which is used for answering the question.
 

Explain how the total energy of a swinging pendulum at any instant of time remains conserved. Illustrate your answer with the help of a labelled diagram.

State the law of conservation of energy.

State and explain the law of conservation of energy with an example.
 

A ball falls to the ground as shown below:

 What is the kinetic energy of ball when it hits the ground?
 

The following data was obtained for a body of mass $1 \mathrm{kg}$ dropped from a height of $5$ meters: Distances above ground and corresponding velocities are mentioned as below:
$5 \mathrm{m}, 0 \mathrm{m}/\mathrm{s}$
$3.2 \mathrm{m}, 6 \mathrm{m}/\mathrm{s}$
$0 \mathrm{m}, 10 \mathrm{m}/\mathrm{s}$
Show by calculations that the above data verifies the law of conservation of energy (Neglect air resistance). ($g = 10 \mathrm{m}/{\mathrm{s}}^2$)