This is a simple pendulum with energy bars and graphs for primary school

1. Click reset to generate a new random angle θ to the vertical downwards y axis.

2. Use sliders θ and L to vary the angle and length of the pendulum respectively.

3. Click play to run the model.

Kinetic energy KE

4.1 Describe in words, when the kinetic energy is zero.

4.2 Describe in words, when the kinetic energy is maximum.

4.3 Describe in words the condition relating velocity to kinetic energy. For example when the velocity is zero, KE is__________. when the velocity is increase, KE __________. when the velocity is greatest, KE is __________.

Potential energy PE

5.1 Describe in words, when the potential energy is maximum.

5.2 Describe in words, when the potential energy is zero.

5.3 Describe in words the condition relating vertical height y to potential energy. For example when the vertical height y is greatest, PE is__________. when the vertical height y is decreasing, PE is__________. when the vertical height y is lowest, PE is__________

5.4 Hence or otherwise, suggest the evidences why is PE sometimes called 'stored energy'?

Total energy TE

6. Notice how the energy bars of kinetic energy (KE), potential energy (PE) and total energy (TE) vary as the pendulum swings with time.Write down the relationship-equation relating KE, PE and TE together.

7. Notice how the energy graphs trails of kinetic energy (KE), potential energy (PE) and total energy (TE) vary as the pendulum swings with time.

8. For each scenario during one swing (once you have picked a starting point), what quantity is conserved (does not change): a) KE, b) PE, c) TE?, how does to total energy change? The total energy is ________________

Other interesting fun activities

1. This model can be used to visualize the relationship that KE + PE = TE.

2. Maximum position (GREEN and ORANGE markers) are added to help teachers and students archor their discussions and argumentations, regarding the position of KEmax and PEmax in relation to one complete swing-period.

3. This model also allows students to click and drag the mass, m for added interactivity and control, thanks to Professor Anne Cox's model

4. Explore your pendulum energy here to test your understanding.