Science 3 · Unit 5: Forces and magnets · Cambridge Primary Science Stage 3

Questions

1. 1. What is friction?

   • a kind of light
   • a force that pulls things to Earth
   • a force from magnets
   • a force between two surfaces that slows movement
   Check

2. 2. What does friction do to moving objects?

   • makes them float
   • makes them magnetic
   • slows them down
   • speeds them up
   Check

3. 3. Where does friction happen?

   • only in space
   • in the middle of an object
   • inside a magnet
   • where the surfaces of two objects rub together
   Check

4. 4. Which surface has the most friction?

   • a wet water slide
   • polished glass
   • smooth ice
   • a rough carpet
   Check

5. 5. Why do you move so fast on a water slide?

   • There is more gravity.
   • The slide is rough.
   • The water pushes you up.
   • The water makes very little friction.
   Check

6. 6. What do we call a surface with lots of friction?

   • transparent
   • slippery
   • grippy
   • magnetic
   Check

7. 7. What do we call a surface with only a little friction?

   • slippery
   • rough
   • sticky
   • grippy
   Check

8. 8. What happens when you rub your hands together?

   • Friction makes them warm.
   • They become magnetic.
   • Nothing happens.
   • They get cold.
   Check

9. 9. Which force pulls a girl down a slide?

   • magnetism
   • gravity
   • upthrust
   • friction
   Check

10. 10. William measured friction: wood 10 N, carpet 20 N, sand 18 N. Which surface had the most friction?

    • sand
    • carpet
    • they were the same
    • wood
    Check

11. 11. William's conclusion was 'The friction on the carpet was 20 N.' Why is this not a good conclusion?

    • It uses newtons.
    • The number is wrong.
    • It is too long.
    • It does not answer his question about which surface had the most friction.
    Check

12. 12. Zara asks 'Does a heavier object have more friction?' What will she change in her fair test?

    • the person pulling
    • the surface
    • the forcemeter
    • the weight of the object
    Check

13. 13. In that fair test, what will Zara measure?

    • the friction, with a forcemeter
    • the length of the table
    • the time of day
    • the temperature
    Check

14. 14. Which way does friction act when you pull a trolley forwards?

    • forwards with you
    • straight down into the floor
    • straight up
    • backwards, against the movement
    Check

15. 15. How does friction help Zara when she is running?

    • It makes her slide.
    • It stops her heart.
    • Her shoes grip the ground so she can push off and stop.
    • It makes her float.
    Check