ENERGY is the ABILITY to CAUSE CHANGE in MATTER. EVERYTHING THAT MOVES HAS ENERGY!
These kids need energy to run. They get their energy from eating healthy foods.
When a roller coaster car climbs a hill, it seems to stop at the top for just a moment. Then it speeds down to the bottom.
Something in motion, like a girl on a pogo stick, has KINETIC ENERGY. KINETIC ENERGY is ENERGY in MOTION.
The roller coaster hovering at the top of a hill has POTENTIAL ENERGY. POTENTIAL ENERGY is the energy something has because of its position or condition.
MECHANICAL ENERGY is the total POTENTIAL ENERGY + KINETIC ENERGY of an object.
The girl pushes the pogo stick spring down. The spring has POTENTIAL ENERGY. When the spring spreads out, the pogo stick goes up and now has KINETIC ENERGY.
As a roller coaster climbs to the top of a hill, it gains POTENTIAL ENERGY. The higher the coaster climbs, the more POTENTIAL ENERGY the cars have.
As the coaster comes down the hill, the POTENTIAL ENERGY decreases because of the changes in KINETIC ENERGY.
MECHANICAL ENERGY = POTENTIAL ENERGY + KINETIC ENERGY
FLASH and BOOM You see lightning flash across the sky. Then you hear a boom that is so loud, it makes your heart pound. Lightning and Thunder are two Forms of Energy.
Lightning can be hotter than the surface of the sun. It makes the air around it rapidly expand. This causes the BOOM of thunder.
Do the Math How far away was that lightning strike? As soon as you see a flash of lightning, count the seconds until you hear thunder. Then divide the number of seconds by 5. This gives you an approximate distance in miles.
LIGHT ENERGY is produced and used in different ways. Light is a form of energy that can travel through space. Plants use light from the sun to make food. PHOTOSYNTHESIS
That same LIGHT ENERGY from the sun allows us to see. Another source of LIGHT ENERGY is electricity. If we couldn’t use electricity to produce LIGHT ENERGY it would be difficult to work or play after dark.
Another form of energy is SOUND ENERGY. Sound is made when something moves back and forth. This motion is called VIBRATION.
Sounds can be described in different ways. PITCH describes how high or low a sound is. LOUD sounds have more energy than quiet sounds.
ENERGY is all around us. You could not do without energy for even one day. CHEMICAL ENERGY is energy that is released by a chemical change. ELECTRICAL ENERGY is energy that comes from electric current.
CHEMICAL ENERGY from the food we eat gives us the energy we need to grow and move. Most cars run on gasoline. Gasoline is a source of chemical energy. Fire releases chemical energy that provides heat and cooks our food.
ELECTRICAL ENERGY is energy that comes from electric current. Anything plugged into a wall outlet uses electrical energy. Electricity is generated using the chemical energy released during the burning of fossil fuels. The sun, wind, and water can also generate electricity.
ENERGY CAN CHANGE FORM Electrical energy changes to light energy when you turn on a light switch. You feel heat energy given off by many light bulbs. Chemical energy in gasoline changes to mechanical energy when a driver presses the gas pedal.
Chemical energy changes into light energy in a glow stick. Glow sticks have a glass tube inside that has chemicals inside. When you bend the glow stick, the tube breaks. The chemicals mix together and when they mix, light energy is given off.
Radio Waves are a form of energy. A remote control sends radio waves to a remote-controlled car. The radio waves change to electrical energy to tell the motor what to do: start – stop – go faster. The car also has batteries to change chemical energy to electrical energy to move the car.
SUMMARY Energy is the ability to cause change in matter. Everything that moves has energy. Kinetic energy is energy of motion. Potential energy is the energy something has because of its position. Mechanical energy is the sum of kinetic energy and potential energy. Light energy allows plants to make food and helps us see and stay warm. Sound energy is caused by vibrations. Energy can change from one form to another.
WATER ENERGY A dam can be used to change the kinetic energy of falling water into electrical energy.
Energy made using falling water is known as HYDROELECTRIC ENERGY. People have always used water’s energy to move things. Before boats had engines, ferries and rafts used the motion of rivers to carry people and goods from place to place.
Mills powered by water have been used for hundreds of years. Water flows over the wheel to turn it. The wheel turns an axle that turns a mill wheel or another device.
1.A river brings water to a dam. The dam holds the water behind it in an artificial lake called a reservoir. 2.Water is released through the dam. The water spins the blades of giant turbines. 3.Each turbine is connected to a generator. The turbine makes the generator spin to produce electricity. 4. The water then flows back into the river.
WIND ENERGY Wind mills, like water mills, have been used for hundreds of years. They move because of the wind. Wind energy is energy produced by moving air.
Windmills used to be used to grind grain. Today, windmills are used to produce electricity. The wind’s kinetic energy causes the turbine’s blades to move. The generator changes this energy of motion into electrical energy.
One wind turbine can make enough electrical energy to power our entire school. Wind and Water are clean energy sources. They do not hurt our environment and they are both renewable resources.
Wind energy is used by kites, gliders and birds as they fly. Sailors capture wind energy to sail the seas.
Renewable Energy is our Future One day we will run out of fossil fuels like coal, petroleum, and natural gas. If we want to continue using electricity, we must find ways to use other sources of energy.
Fossil fuels are NONRENEWABLE. When they are gone, they’re gone. Water and wind are renewable sources of energy. Biofuels, which are made from living things, are renewable resources too.
Solar energy is a renewable source of energy. Windmills and water energy are also renewable.
Another renewable energy source is HYDROGEN. This car has a tank filled with hydrogen instead of gasoline. The hydrogen goes to a fuel cell, where the Hydrogen mixes with oxygen to produce electricity.
SUMMARY Wind and water are two important sources of renewable energy. People have long used water’s energy to move people and things. Windmills were often used to grind grain. Today, we use wind energy and water energy to drive generators. The generators change mechanical energy into electrical energy.