ENERGY

Atoms vibrating in a solid. The atoms have energy because of

their motion

Forms of energy• Kinetic energy- is the energy due to motion.

All moving objects have kinetic energy.

• Potential energy- is the energy which an object has because of its changed position, shape or state. There are different types of potential energy-

Potential energy• Gravitational Potential energy- A stone

held up in the air can do work when dropped because gravity will pull it downwards. The stone has gravitational potential energy.

• Elastic Potential energy- A stretched rubber band can do work when released so can a compressed spring.

• Chemical energy- The burning of a substance to produce heat is due to the chemical energy of the substance. Eg-energy stored in food and other fuels. A bullet fired from a gun is an illustration of chemical energy.

• Electrical energy- In circuits, the current is a flow of tiny charged particles called electrons. These come from atoms. Electrons can transfer energy from – a battery to a light bulb.

contd…

• Nuclear energy- energy is stored in the centre (nucleus) of an atom. This is made up of particles, held there by strong forces.

Thermal energy- When hot objects cool down, their atoms and molecules slow down and lose energy. This is thermal energy. Eg: in a car engine, burning fuel

contd…

• Radiated energy- Sun radiates energy(light) because of nuclear fusion reactions deep inside it. Loudspeaker radiate sound.

contd…

• Sound energy- When sound waves strike the ear drum, it begins to vibrate and makes hearing possible.These carry energy.

• Light energy- Light is a form of energy. It is light energy that enables us to see the objects around us.

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