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8th grade · Science · Unit 12 of 16

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.

Alabama Course of Study content standard: 8.13; 8.14; 8.15 · kinetic energy, mass and speed, potential energy, and energy being conserved

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 Alabama

In the Alabama Course of Study, this is unit 12 of 16 in 8th grade Science, after Fields & Forces at a Distance and before Work, Energy & Efficiency.

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: Alabama State Department of Education (ALSDE)

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 pendulum swings fastest at…

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

  2. Question 2

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

    • gets lighter
    • stops
    • speeds up
    • slows down

  3. Question 3

    A ball thrown upward slows down because kinetic energy changes into…

    • nothing
    • potential energy
    • mass
    • light

  4. Question 4

    Potential energy is…

    • the speed of light
    • a type of force
    • stored energy due to position or condition
    • energy of motion

  5. Question 5

    Kinetic energy is energy of…

    • heat only
    • position
    • motion
    • light only

  6. Question 6

    A roller coaster's second hill is lower than the first because…

    • the cars get heavier
    • energy is created
    • some energy changes to heat and sound by friction
    • gravity gets stronger

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