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Year 9 Science — Forces: contact and non-contact

Sort forces by whether they need the objects to touch, read a spring balance, and keep weight and mass apart.

Name: ________________________

  1. 1.An object is carried to the Moon. Which of these changes, and which stays put?

    • a) Neither changes
    • b) Its weight changes; its mass stays the same
    • c) Its mass changes; its weight stays the same
    • d) Both change

  2. 2.A closed empty bottle is pushed down into a bucket of water and released. It shoots back to the surface. What has pushed it?

    • a) The gravitational force of the Earth, acting upwards in water
    • b) Friction between the bottle and the water
    • c) Upthrust, the upward force a liquid applies on an object placed in it
    • d) Muscular force still stored in the bottle from the push

  3. 3.Sort these forces by whether the two objects have to be touching for the force to act.

    Groups: Contact force · Non-contact force

    • Muscular force
    • Gravitational force
    • Friction
    • Magnetic force
    • Electrostatic force

  4. 4.What is the SI unit of force called? Give the one word.

  5. 5.A spring balance measures up to 10 N, with a bigger mark at each newton. Which mark is at 6 N?

    Mark the line with an X.

    012345678910

  6. 6.Two balloons are rubbed with the same woollen cloth and hung near each other. What do they do, and why?

    • a) They move together, because rubbing makes both of them sticky
    • b) They hang still, because rubbing wool on rubber charges neither of them
    • c) They move together, because they have picked up charges of opposite kinds
    • d) They move apart, because they have picked up charges of the same kind and like charges repel

  7. 7.A ball is thrown straight up. Starting from The object moves straight up, put what happens next back into order.

    • It stops momentarily at the top
    • The object moves straight up
    • It falls back down, its speed increasing
    • Its speed goes on decreasing

  8. 8.A box is pushed to the right across a table. In which direction does friction act on it?

    • a) Downwards, into the table
    • b) To the right, along with the push
    • c) Upwards, away from the table
    • d) To the left, opposite to the way the box is moving

Answer key — Year 9 Science — Forces: contact and non-contact

  1. 1. b) Its weight changes; its mass stays the same
  2. 2. c) Upthrust, the upward force a liquid applies on an object placed in it
  3. 3. Muscular force → Contact force; Friction → Contact force; Magnetic force → Non-contact force; Electrostatic force → Non-contact force; Gravitational force → Non-contact force
  4. 4. newton
  5. 5. 6
  6. 6. d) They move apart, because they have picked up charges of the same kind and like charges repel
  7. 7. 1. The object moves straight up 2. Its speed goes on decreasing 3. It stops momentarily at the top 4. It falls back down, its speed increasing
  8. 8. d) To the left, opposite to the way the box is moving