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Learn about the different forms of energy including potential, kinetic, mechanical, electrical, light, thermal, and sound energy. Discover how they are stored and how they impact the world around us.
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ENERGY is the ability to make something MOVE or CHANGE
In fact….. NOTHING would happen without ENERGY
Energy is either Potential or Kinetic
POTENTIAL ENERGY is STORED ENERGY Potential energy is stored energy as the result of its position. .
KINETIC ENERGY is ENERGY IN MOTION Kinetic energy is the energy an object has due to its motion.
One way to remember forms of KINETIC ENERGY is: MELTS M echanical Energy – Energy of motion E lectrical Energy – Energy that flows through wires L ight Energy – Energy that enables us to see T hermal (or Heat) Energy – Energy that has moving particles S ound Energy – Energy with vibrations that enables us to hear
MECHANICAL ENERGY MELTS (1) The iron hammer on its own has no kinetic energy, but it has some potential energy (because of its weight). (2) To drive a nail into the piece of wood, he has to lift the iron hammer up, (this increases its potential energy because if its high position). (3) He swings it downwards (now has kinetic energy) to hit the nail. The sum of the potential and kinetic energy that the hammer has to drive in the nail is called the mechanical energy. Even though it changed from potential energy to kinetic energy, the mechanical energy stays the same.
MECHANICAL ENERGY MELTS Another example is a roller coaster. When it is on its way up, it is using kinetic energy since the energy is in motion. When it reaches the top it has potential (or stored) energy. When it goes down the hill it is using kinetic energy again. The sum of the potential and kinetic energy that the roller coaster has is mechanical energy.
MELTS Electrical Energy Electrical energy is energy that moves through wires. It makes a light bulb light up, or makes us hear a radio, or hear and see what’s on TV. This lamp is using electrical energy, and giving off light and heat energy. The electrical energy changes into light and heat energy. However, unlike a TV, the lamp does not give off, or change into, sound energy.
MELTS Light Energy Light energy is the only form of energy that we can actually see. Many things that give off light, can also give off heat (like a light bulb). Light moves in straight lines. It does not bend or curve. Objects can absorb light, which means it doesn’t bounce back to the source, or go through it (like it does with glass). We can make shadows this way because we block (or absorb) some of the light with our bodies.
MELTS Light Energy A surface can reflect, or bounce back, light. Light can change direction. Things that reflect light well are smooth glass, metal, or water. And, of course a mirror. Here’s how it works. A light from any source reflects off of you in all directions. The light that reflects off you to the mirror, changes direction, and travels back to your eyes. This is why you can see your reflection in a mirror. The fact that light reflects, or bounces, off of things is the reason we can see anything. We can see things as a result of light reflecting off objects and traveling to our eyes. Without light, objects would not be seen. Without light, there is no sight!
MELTS Light Energy Light can change direction in a different way. Light can also refract, or bend, when it moves from one clear material (like air) to another (like water). This is because the light slows in water, making it change its path. air the point at which the light enters and leaves the water When light hits a lens on eyeglasses, a microscope, a telescope, or a camera, it also refracts. This is why these things can magnify. water Light slows down when it moves from air to water and it speeds up when it moves from water to air. The change in speed makes the light refract, or bend. This is what causes the straw to look broken where the air and water meet.
MELTS Thermal or Heat Energy Heat energy can flow between two objects. For example, when you wrap your hands around a warm mug, the heat energy flows directly from the warm mug to your hands. This raises your skin temperature, and you feel heat. There doesn't have to be direct contact between a hot object and the person for a person to feel heat energy, because heat can also travel through air (like fire). Things that give off heat, often give off light (like fire).
MELTS Sound Energy Sound is produced when a force causes something to vibrate — the energy is transferred in the air as a wave. A vibrating drum transfers energy to the room as sound. Kinetic energy from the moving air molecules transfers the sound energy to our ears. We use sound energy all the time. We even use sound energy when we talk with each other.
So…… Energy is all around us. Energy is the ability to make things move or change. There are many forms of energy, like potential, kinetic, heat, light, sound, and electricity. Kinetic energy is energy in motion. Electrical, heat, light, sound, and motion are forms of kinetic energy. There is kinetic energy even though we might not see it. Energy that is not kinetic is potential. Potential energy is stored energy. Energy can change from one form to another. For example potential energy can change to kinetic energy.
