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Grade 8 · Science · Unit 14 of 16

Simple Machines & Advantage

Levers, ramps, pulleys and mechanical advantage

What your child practises

Identifying the six simple machines, finding mechanical advantage from input and output forces, understanding that machines trade force for distance, and how innovations such as combine harvesters and robotics raised productivity.

Nunavut Curriculum approved guide: Nunavut adaptation of Alberta Science 7–9 (2003), Unit D: Mechanical Systems · simple and compound machines

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Which is a technology that increased farm productivity?

    • the hand sickle only
    • the paper map
    • the wooden spoon
    • the combine harvester, which cuts and separates grain in one pass

  2. Question 2

    How have robotic arms in car factories changed productivity?

    • They make every car different by hand.
    • They can weld and assemble the same part quickly and repeatedly.
    • They need no electricity.
    • They are never programmed.

  3. Question 3

    Mechanical advantage is the ratio of…

    • input force to time
    • mass to volume
    • output force to input force
    • work to energy

  4. Question 4

    Which part of a lever is the pivot?

    • the effort
    • the fulcrum
    • the load
    • the wheel

  5. Question 5

    An input force of 40 N lifts a load that needs 120 N. What is the mechanical advantage?

    answer box

  6. Question 6

    A machine has a mechanical advantage of 3. You apply an input force of 30 N. What output force does it give, in N?

    answer boxN

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