Simple machines & forces

A force is a push or a pull. Simple machines make work easier by changing the size or direction of a force needed to do a job. A lever is a bar that pivots around a fixed point (the fulcrum) to lift things with less effort, like a seesaw or a crowbar. A pulley uses a wheel and rope to change the direction of a pulling force, making it easier to lift heavy loads.

Key terms

Force:

A push or a pull on an object.

Lever:

A bar that pivots around a fixed point (fulcrum) to lift or move things.

Pulley:

A wheel and rope system that changes the direction of a force.

Questions

1. 1. A force is a:

   • Push or a pull
   • Type of machine only
   • Colour
   • Sound

2. 2. A seesaw is an example of a:

   • Pulley
   • Lever
   • Wheel
   • Screw

3. 3. The fixed point a lever pivots around is called the:

   • Solvent
   • Fulcrum
   • Solute
   • Pulley

4. 4. A pulley uses a wheel and a:

   • Rope
   • Battery
   • Magnet
   • Screwdriver

5. 5. Simple machines are used to:

   • Make work easier
   • Make work harder
   • Replace all forces
   • Only look nice

6. 6. Pushing a shopping trolley is an example of using a:

   • Pulling force
   • Pushing force
   • No force at all
   • Magnetic force only

7. 7. A crowbar prying open a lid is an example of a:

   • Lever
   • Pulley
   • Wheel and axle
   • Screw

8. 8. A flagpole using a rope and wheel to raise a flag is an example of a:

   • Lever
   • Pulley
   • Wedge
   • Inclined plane

9. 9. Moving the fulcrum of a lever closer to the object being lifted makes lifting:

   • Easier
   • Harder
   • Impossible
   • No different

10. 10. A ramp used to roll a heavy box up instead of lifting it is an example of a/an:

    • Inclined plane
    • Pulley
    • Lever
    • Screw

11. 11. A doorknob is an example of which simple machine?

    • Wheel and axle
    • Pulley
    • Lever only
    • Wedge

12. 12. Simple machines change the size or direction of a force to:

    • Reduce the effort needed to do work
    • Remove the need for any force
    • Make objects heavier
    • Make objects disappear

13. 13. An axe blade is an example of a:

    • Wedge
    • Pulley
    • Wheel
    • Lever only

14. 14. Using a pulley to lift a bucket from a well changes the direction of the force so that you:

    • Pull down to lift the bucket up
    • Push up to lift it down
    • Need no force at all
    • Must pull sideways only

15. 15. A pair of scissors uses which two simple machines together?

    • Levers and wedges
    • Pulleys and screws
    • Wheels only
    • Inclined planes only

16. 16. Why does a longer lever arm generally require less force to lift the same object?

    • It spreads the same work over a longer distance, reducing the force needed
    • Longer levers are magic
    • It increases the object's weight
    • It has no effect

17. 17. A block and tackle (multiple pulleys together) mainly helps by:

    • Multiplying the lifting force with less individual effort
    • Making the load heavier
    • Removing the need for any rope
    • Only working underwater

18. 18. A wheelbarrow is a combination of which simple machines?

    • A lever and a wheel and axle
    • A pulley and a screw
    • A wedge only
    • None, it uses no simple machines

19. 19. Screws are essentially a type of:

    • Inclined plane wrapped around a cylinder
    • Pulley
    • Lever only
    • Wheel with no axle

20. 20. Why are ramps often built next to stairs for wheelchairs?

    • A ramp (inclined plane) reduces the force needed compared to lifting straight up
    • Ramps are decorative only
    • Ramps remove the need for any force
    • Stairs are always easier

21. 21. Bicycle gears change the amount of force needed to pedal by acting as a type of:

    • Wheel and axle system
    • Pulley only
    • Lever only
    • Screw only