Light, Heat and Sound Energy

What are the uses of light energy?

• Light energy from the sun enables plants with chlorophyll to make food.
• Light energy enables us to see.
• Some equipment, as mentioned below, uses light energy to function.

-Camera ('Captures' images on a film to make photographs)
-Projector (Shines images onto a screen, such as in movies
-Traffic lights (Differently-coloured lights guide traffic on the roads)
-Runway lights (Help planes land or take off)
-Laser (Produces a strong beam of light that can cut through very hard materials which sometimes is also used in surgery)


What are the Sources and Uses of Heat Energy?

• Heat energy is a form of energy that can cause an object to change its temperature or state.
• Heat energy from the sun keeps living things warm in order for them to survive.
• Some equipment, as mentioned below, are sources of heat energy.

-The Sun (Warms the surface of the Earth to a temperature suitable for living things, dries clothes and dries food, allowing the food to be kept for a long time before consumption)
-Electric Kettle (Boils water)
-Electric Stove, Rice Cooker, Oven and Toaster (Cooks Food)
-Electric Iron (Irons clothes)
-Wood (Provides warmth for our bodies and provides heat for cooking food)
-Coal, Natural Gas and Oil (Provides warmth for our bodies, provides heat for cooking food, provides heat in industries to melt metals or to kill germs in canned food, and turns water into steam that drives turbines in power stations to generate electricity)

Heat energy can also be produced by rubbing our hands together (Friction, the topic on Forces, which we will cover after this topic.)

What are The Properties Of Sound Energy?

• Sound is a form of energy that we can hear. It is produced by vibrating objects. (A vibrating object moves back and forth, often very quickly)
• Sound travels outwards from the object producing it towards our ears. Sound needs a medium to travel through, or else it cannot be heard. (Air, water and wood are all mediums which sound can travel through)
• There are many types of sounds. Some examples of their sources are listed below.

- Humans (We produce Speech, Song and Noise for communication)
-Sirens of ambulance or fire engines (They produce loud noises mostly for communication to warn people of an emergency, asking them to give way)
-Fire alarms in buildings (They produce loud noises as well, as a communication to warn people of a fire)
-Musical instruments (Trumpets, Pianos, Cellos, Drums, Cymbals, etc. They produce music for entertainment purposes which is pleasant to listen to.