Energy: Forms and Transfer — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. When you ride a bike, the chemical energy from food in your body changes into kinetic energy of motion.
Grade 4 science traces this chain: food has chemical energy, your muscles transform it into kinetic energy that moves the bike forward.
2. A microwave oven changes electrical energy into heat energy that warms your food.
Grade 4 lessons describe how microwaves transform electrical energy into heat (thermal) energy. This warms water in food, making it hot.
3. When you pluck a guitar string, motion energy transforms into sound waves you can hear.
Grade 4 students learn that vibrating strings push air, creating sound waves. Motion energy becomes sound energy that travels to your ears.
4. A flashlight changes the chemical energy in its battery into electrical energy and then into light energy.
Grade 4 science teaches the flashlight chain: chemical to electrical to light. The bulb is where electrical energy transforms into useful light.
5. When water flows through a dam, its kinetic energy can spin a turbine and make electrical energy.
Grade 4 students learn that hydroelectric dams transfer kinetic energy from moving water into electrical energy used in homes.
6. A toaster turns electrical energy into heat energy and a small amount of light energy when the wires glow red.
Grade 4 science notes that toaster wires get so hot they emit light along with heat. Most energy becomes heat, but some becomes light.
7. A solar panel transforms light energy from the sun into electrical energy.
Grade 4 lessons explain that solar panels capture sunlight and turn light energy into electrical energy that powers buildings.
8. When you rub your hands together quickly, kinetic energy turns into heat energy that warms your skin.
Grade 4 students learn that friction is a real-world transfer where motion changes into heat. Rubbing hands warms them up this way.
9. A speaker takes electrical energy and changes it into sound energy that travels through the air.
Grade 4 science describes how speakers vibrate to push air, transforming electrical energy into sound energy that reaches your ears.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Bicycle while pedaling
→ Chemical (food) to kinetic (motion)
Chemical (food) to kinetic (motion)
Microwave oven warming soup
→ Electrical to heat (thermal)
Electrical to heat (thermal)
Guitar string vibrating
→ Motion to sound waves
Motion to sound waves
Solar panel on a roof
→ Light to electrical
Light to electrical
Grade 4 students match real-world devices to the energy transformations they perform. Each item shows a clear input form changing to a useful output form.