Energy changes Energy changes are happening all the time. Green plants are changing light energy from the sun into chemical energy. The chemical energy in the food you ate earlier is being changed into heat and motion energy in your body. The light bulb in the room is changing electric energy into light and heat energy.
Activity Investigate energy changes A
Fig. 4 shows a Crooke’s radiometer. 1. Place the radiometer in shadow and observe what happens.
2. Place the radiometer in sunlight and observe what happens.
3. Describe the energy changes taking place.
B 1. Put a toy car or marble on a slope and hold it. 2. Release it. 3. Describe the energy changes taking place.
Fig. 5 C
Materials: Battery, wires, crocodile clips, buzzer 1 . Connect these materials to make the buzzer ring. 2 . Describe the energy changes taking place.
Fig. 6 Fig. 4 A Crooke’s radiometer.
Activity Energy changes: Look around. How many energy changes can you identify at this moment?
D 1. Light a Bunsen burner. 2. Describe the energy changes taking place.
