Energy can be neither created nor destroyed but changed from one form into another. When energy is changed from one form into another a different form of energy is formed. For example when petrol burns in a car engine the chemical potential energy of stored in the petrol produces the kinetic energy of motion. This is represented by an energy equation:
Examples of Energy Equations:
Chemical potential energy from wax.
Chemical potential energy —–> light + heat energy
Chemical potential energy from petrol.
Chemical potential energy ——-> Kinetic energy of motion + sound and heat energy
Energy can exist in different forms.
• Energy can be changed from one form to another.
• Energy is not a tangible substance.
• Energy is only detected when some change occurs.
Energy is defined as the capacity to do work and is measured in Joules (J).
Examples of energy forms
• Food is chemical potential energy.
• Extending or compressing a spring is elastic potential energy.
• Gaining or losing height is gravitational potential energy.
• Noise is produced by sound energy.
• The stars in the night sky produce solar energy.
• A lead/acid car battery stores chemical potential energy.
• An atomic power plant produces nuclear energy.