Activity 1

To demonstrate pressure of potential energy
Materials and Apparatus
1. A heavy stone
2. A bucket full of water
3. A strong inelastic rope; and
4. Smooth pulley

Procedures:
 Collect the heavy stone, using a strong rope tie it to a bucket of water
 Pass the rope over smooth pulley fixed to a support.
 Hold stationary the heavy stone at height “h” above the ground
 Release the stone

Results and observations:
 When the stone released the bucket of water will start to rise.
 The stone is said to have potentials energy because of its position above the ground.

 Lifting a body of mass “m” to a height “h” above the ground requires work to be done
against gravity. Work = Mgh  


Activity 2

Aim: to investigate the law of conservation of energy by a simple pendulum.
Materials and Apparatus: A pendulum bob and light inelastic string.

Procedures;

 Pull the bob of a simple pendulum in position A so that it is at height “h” above position B.
Release the bob so that it swings to position C via the lowest position B and back to A.
Consider the figure below:


Observation
When the bob is at position A, it possesses potential energy only due to the height “h” which is equal to “Mgh”.

As it swings downwards to position B, the height decreases, and as the result it loses potential energy.
 The bob has Vmax and hence K.Emax at B. The height at B is zero, thus the P.E is zero.
 As it swings towards C, the P.E increases and reaches its maximum again in position C, where the Kinetic Energy is zero. At position D, the energy of the bob is party potential and party Kinetic.