Science 7 · Unit 3: Forces and energy · Cambridge Lower Secondary Science Stage 7

Questions

1. 1. Gas is burned for heating. What is the energy change?

   • kinetic → thermal
   • chemical → thermal
   • thermal → chemical
   • electrical → thermal
   Check

2. 2. An electric lamp is switched on. What is the useful energy change?

   • electrical → light
   • electrical → thermal
   • light → electrical
   • chemical → light
   Check

3. 3. A music player is switched on. What is the useful energy change?

   • electrical → light
   • sound → electrical
   • electrical → sound
   • chemical → kinetic
   Check

4. 4. A petrol engine drives a car. What is the useful energy change?

   • chemical → kinetic
   • thermal → chemical
   • kinetic → chemical
   • electrical → kinetic
   Check

5. 5. A ball is dropped. What is the energy change as it falls?

   • gravitational potential → kinetic
   • kinetic → gravitational potential
   • elastic → kinetic
   • chemical → kinetic
   Check

6. 6. Look at the graph. What happens to the water's temperature as more thermal energy is transferred?

   • It increases.
   • It decreases.
   • It stays the same.
   Check

7. 7. Look at the graph. What was the water's temperature before any thermal energy was transferred?

   • 10 °C
   • 20 °C
   • 0 °C
   • 70 °C
   Check

8. 8. Look at the graph. What was the water's temperature after 25 000 J had been transferred?

   • 80 °C
   • 60 °C
   • 10 °C
   • 70 °C
   Check

9. 9. Look at the graph. How much thermal energy raised the water from 10 °C to 34 °C?

   • 10 000 J
   • 15 000 J
   • 5000 J
   • 24 000 J
   Check

10. 10. Look at the graph. How much thermal energy raised the water from 10 °C to 22 °C?

    • 10 000 J
    • 2200 J
    • 5000 J
    • 12 000 J
    Check

11. 11. In this investigation, what must stay constant?

    • the mass of water used
    • the temperature of the water
    • the thermal energy supplied
    • the time of day
    Check

12. 12. A jumping toy is pushed down, squeezing a spring inside. Which energy is stored?

    • kinetic
    • chemical
    • sound
    • elastic
    Check

13. 13. The jumping toy is released and jumps up. What is the energy change as it leaves the surface?

    • chemical → kinetic
    • kinetic → elastic
    • gravitational potential → elastic
    • elastic → kinetic
    Check

14. 14. As the jumping toy rises to its highest point, what is the energy change?

    • kinetic → gravitational potential
    • gravitational potential → kinetic
    • elastic → chemical
    • thermal → kinetic
    Check

15. 15. Which energy store is biggest when the toy is at its highest point?

    • chemical
    • elastic
    • gravitational potential
    • kinetic
    Check

16. 16. The jumping toy falls back down onto the surface. What is the energy change as it falls?

    • kinetic → gravitational potential
    • gravitational potential → kinetic
    • elastic → kinetic
    • kinetic → elastic
    Check

17. 17. When the toy hits the surface and stops, where does its kinetic energy go?

    • to sound and thermal energy
    • back into elastic energy in the spring
    • It is destroyed.
    • to chemical energy
    Check