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7th grade · Science · Unit 5 of 8

Motion, Forces & Newton’s Laws

Speed, velocity, acceleration, friction and the Laws of Motion.

What your child practices

Practices speed, velocity, acceleration, forces, friction, gravity and Newton's three Laws of Motion, with stability. It follows the Grade 8 science skill descriptors on motion and stability and the Laws of Motion in the New Brunswick curriculum.

Arizona Academic Standards learning standard: 7.P3U1.4; 7.P3U1.3 · Newton's laws of motion

How we explain it

Children can open this short lesson before they practice.

  1. Speed = distance ÷ time. Velocity is speed with a direction.
  2. Force is measured in newtons. Friction and gravity are forces.
  3. Newton’s laws: objects keep doing what they’re doing unless a force acts; more force means more acceleration; every push has an equal push back.

Example: A cyclist rides 30 m in 6 s. What is her speed? Speed = distance ÷ time. 30 ÷ 6 = 5. Answer: 5 m/s

Motion, Forces & Newton’s Laws in Arizona

In the Arizona Academic Standards, this is unit 5 of 8 in 7th grade Science, after How Plants Work and before Electromagnets & Generators.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: Arizona Department of Education

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

    A car goes at 80 km/h for 3 hours. How far does it travel?

    • 27 km
    • 160 km
    • 83 km
    • 240 km

  2. Question 2

    What is friction?

    • a force that opposes motion between touching surfaces
    • a kind of magnetism
    • a force that speeds things up
    • a kind of gravity

  3. Question 3

    Unbalanced forces on an object cause…

    • a change in its motion
    • balance
    • friction to vanish
    • no change

  4. Question 4

    If the same force pushes a light cart and a heavy cart, which accelerates more?

    • the heavy cart
    • the light cart
    • both the same
    • neither

  5. Question 5

    What is the difference between mass and weight?

    • mass is a force
    • mass is the amount of matter, and weight is the force of gravity on it
    • weight is the amount of matter
    • they are the same

  6. Question 6

    Why do seat belts and airbags protect people?

    • they speed up the body
    • they spread out the force and slow the body gradually
    • they remove inertia
    • they stop gravity

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