Energy in Action
Two identical toy cars roll down a track. One rolls faster than the other. Which car has more energy of motion?
The faster car
Moving air turns a wind turbine. What form of energy does the turbine produce for use in homes?
Electrical
Classify each energy source as renewable or non-renewable: sunlight, wind, and coal.
Sunlight: renewable
wind: renewable
coal: non-renewable.
Renewable sources are naturally replenished; coal is a fossil fuel that takes a very long time to form.
A battery-powered toy car moves across the floor. Describe the energy change that makes the car move.
The battery’s stored energy changes into electrical energy, which is changed into motion energy as the car moves.
A town decides to use Solar energy to power the homes instead of fossil fuels for energy. Why might the town decide to use solar energy? Give two reasons.
It is renewable and it has less pollution.
A lamp is switched on. What two forms of energy does it produce from electrical energy?
Light and heat
Water flowing through a dam turns equipment that generates electricity. What energy change is taking place?
Motion to electrical
A student puts a solar cooker under a thick roof overhang. The cooker heats food slowly. What change in location would likely help most, and why?
Move the cooker into direct sunlight. Sunlight transfers energy to the cooker, where it is changed into heat that warms the food.
Two identical balls roll across a floor. One rolls faster. Which has more energy of motion, and why?
The faster ball has more energy of motion because it is moving faster.
At a hydroelectric dam, moving water turns a turbine connected to a generator. What energy change does the generator help make?
Electrical energy from the moving water
A blender is plugged in and its blades spin. What energy change helps explain the blades’ motion?
Electrical to motion
A book falls from a desk and lands with a thump. How does the book’s motion produce sound?
When the moving book hits the desk or floor, energy is transferred during the collision and sound is produced.
A generator converts the energy of moving water from a dam into electrical energy. Describe this energy conversion.
Motion to electrical
Classify sunlight, coal, and natural gas as renewable or non-renewable energy sources.
Sunlight is renewable; coal and natural gas are non-renewable.
Wind turbines use wind to generate electricity. What kind of energy resource is wind?
Renewable
Two identical balls roll across a floor. One moves faster than the other. Which ball has more energy of motion?
The faster one
A student turns a hand-crank generator, and a small light turns on. Describe the energy change that makes the light work.
The student’s motion turns the generator, changing motion energy into electrical energy; the light changes electrical energy into light.
A battery stores chemical energy. When a battery is connected to a toy, the chemical energy is converted into electrical energy that makes the toy move. What type of energy transfer is this?
chemical to motion
A lamp changes electrical energy into light and heat. Make a claim about the energy change and give a reason based on what the lamp produces.
The lamp changes electrical energy into light and heat energy because it gives off light and becomes warm.
A student pedals a bicycle connected to a small generator, which lights a bulb. What energy change makes the bulb light?
Motion energy from the pedalling.
A doorbell uses electrical energy to make a sound and light up. Name the two forms of energy produced.
The doorbell changes electrical energy into sound and light.
A toaster changes electrical energy into heat to toast bread. It also makes a clicking sound when it switches off. What form of energy does the click produce?
Sound energy. The toaster’s click produces sound.
A wind turbine is a machine that uses wind energy to generate electricity. Which type of energy resource is wind?
A renewable energy source
Two balls are dropped from the same height. Ball A is moving faster than Ball B when they hit the ground. Which ball has more energy?
Ball A
Name one action that is a good way to save energy at home.
turn off the lights when not using them
use candles
unplug devices