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

Questions

1. 1. Which units can be used to measure mass?

   • m and cm
   • N and kg
   • g and kg
   • N only
   Check

2. 2. What is weight measured in?

   • newtons (N)
   • kilograms (kg)
   • metres (m)
   • grams (g)
   Check

3. 3. What is mass?

   • how big an object is
   • the quantity of matter in an object
   • something that changes with the strength of gravity
   • the force of gravity on an object
   Check

4. 4. Which changes depending on the strength of gravity?

   • mass
   • the quantity of matter
   • weight
   • the number of particles
   Check

5. 5. Match each description to weight or mass.

   • the force of gravity on an object
   • the amount of matter in an object
   • stays the same when gravity changes
   • is less on the Moon than on Earth

   • weight
   • mass
   • mass
   • weight
   Check

6. 6. Weight (N) = mass (kg) × 10 (N/kg). A bag has a mass of 10 kg. What is its weight?

   • 1 N
   • 100 N
   • 100 kg
   • 10 N
   Check

7. 7. Which piece of equipment is used to find the mass of an object?

   • a top pan balance
   • a force meter
   • a ruler
   • a measuring cylinder
   Check

8. 8. Which of these values is a mass: 1.5 N, 4.91 m, 6.04 g or 650 kN?

   • 650 kN
   • 1.5 N
   • 4.91 m
   • 6.04 g
   Check

9. 9. Which of these values is a mass: 120 g, 975 mm, 1.5 N or 650 kN?

   • 650 kN
   • 975 mm
   • 120 g
   • 1.5 N
   Check

10. 10. Weight (N) = mass (kg) × 10 (N/kg). A large rock has a weight of 8000 N. What is its mass?

    • 80 000 kg
    • 800 kg
    • 800 N
    • 8000 kg
    Check

11. 11. Weight (N) = mass (kg) × 10 (N/kg). An elephant has a weight of 40 000 N. What is its mass?

    • 4000 N
    • 4000 kg
    • 40 000 kg
    • 400 000 kg
    Check

12. 12. Weight (N) = mass (kg) × 10 (N/kg). An apple has a weight of about 1 N. What is its mass?

    • about 1 kg
    • about 0.1 N
    • about 10 kg
    • about 0.1 kg
    Check

13. 13. Objects on Mars weigh less than on Earth. Gravity on Earth is 10 N/kg. What is the strength of gravity on Mars?

    • also 10 N/kg
    • It is not possible to predict.
    • less than 10 N/kg
    • more than 10 N/kg
    Check

14. 14. A rock has a mass of 3 kg on Earth. What is its mass on Mars?

    • 3 kg, the same as on Earth
    • 0 kg
    • less than 3 kg
    • more than 3 kg
    Check

15. 15. In which direction does the force of gravity from the Earth act?

    • away from the centre of the Earth
    • towards the Sun
    • always towards the North Pole
    • towards the centre of the Earth
    Check

16. 16. An astronaut travels away from the Earth in a spacecraft. What happens to the Earth's pull of gravity on her?

    • It gets stronger.
    • It gets weaker.
    • It stays the same.
    • It suddenly stops at the top of the sky.
    Check

17. 17. How is the force of gravity between two masses similar to the force between two magnets?

    • Both need the objects to touch.
    • Both act without touching, and both get weaker with distance.
    • Both can push and pull.
    • Both only act on metals.
    Check

18. 18. How is gravity different from the force between two magnets?

    • Gravity only attracts, but magnets can attract or repel.
    • Gravity can repel, but magnets only attract.
    • Gravity needs objects to touch.
    • Gravity only acts on magnets.
    Check

19. 19. A book with a weight of 5 N rests on a level table. How big is the contact force from the table?

    • 0 N
    • 5 N, pushing up
    • 10 N, pushing up
    • 5 N, pushing down
    Check

20. 20. Zara hangs masses on a piece of equipment with a scale in newtons. What is it?

    • a top pan balance
    • a force meter
    • a ruler
    • a measuring cylinder
    Check