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8th grade · Science · Unit 4 of 11

Kinetic & Potential Energy

Energy of motion and stored energy.

What your child practices

Practices how kinetic energy depends on mass and speed, how potential energy changes with position, and how energy transfers change an object's motion.

New York State Learning Standards learning standard: MS-PS3-1; MS-PS3-2 · kinetic energy, mass and speed, and potential energy and position

How we explain it

Children can open this short lesson before they practice.

  1. Kinetic energy is energy of motion; it grows with mass and speed.
  2. Potential energy is stored by position; higher up means more.
  3. Energy changes form: a falling ball turns potential into kinetic energy.

Example: Where does a roller coaster have the most kinetic energy? Kinetic energy is greatest where it is fastest. It is fastest at the bottom of a hill. Answer: at the bottom of the hill

Kinetic & Potential Energy in New York

In the New York State Learning Standards, this is unit 4 of 11 in 8th grade Science, after Motion, Forces & Newton’s Laws and before Fields & Forces at a Distance.

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: New York State Education Department (NYSED)

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 has more kinetic energy?

    • A parked truck
    • A truck at 50 km/h
    • A ball at rest
    • A bike at 50 km/h

  2. Question 2

    Pushing a cart transfers energy to it, so the cart…

    • slows down
    • speeds up
    • gets lighter
    • stops

  3. Question 3

    A pendulum swings fastest at…

    • it never moves
    • the bottom of its swing
    • the side
    • the top

  4. Question 4

    A roller coaster at the top of a hill has the most…

    • gravitational potential energy
    • light energy
    • sound energy
    • kinetic energy

  5. Question 5

    Water held behind a dam has…

    • sound energy only
    • gravitational potential energy
    • no energy
    • kinetic energy only

  6. Question 6

    A car goes from 30 km/h to 60 km/h. Its KE becomes…

    • 2 times larger
    • 4 times larger
    • the same
    • half

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