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9th grade · Science · Unit 9 of 10

Energy & Magnetism

Conservation of energy, efficiency and electromagnets.

What your child practices

Practices the law of conservation of energy, potential and kinetic energy, efficiency, and the link between electric current and magnetic fields in electromagnets and generators.

Arizona Academic Standards learning standard: HS.P4U1.8; HS.P2U1.5 · conservation of energy and magnetic fields from electric currents

How we explain it

Children can open this short lesson before they practice.

  1. Energy is never created or destroyed, only changed. Higher objects have more potential energy; faster ones more kinetic energy.
  2. Every magnet has two poles, north and south.
  3. Moving a coil of wire in a magnetic field makes electric current: that is how a generator works.

Example: Where does a roller coaster have the most potential energy? Potential energy depends on height. It is highest at the top. Answer: at its highest point

Energy & Magnetism in Arizona

In the Arizona Academic Standards, this is unit 9 of 10 in 9th grade Science, after Evolution & Selection and before Forces, Motion & Momentum.

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

    Which energy source is non-renewable?

    • natural gas
    • solar
    • hydro

  2. Question 2

    Energy of motion is…

    • potential energy
    • kinetic energy
    • chemical energy

  3. Question 3

    A magnet is surrounded by a…

    • wire
    • magnetic field
    • battery

  4. Question 4

    A battery stores energy as…

    • chemical potential energy
    • light
    • kinetic energy

  5. Question 5

    An electrical generator works by moving a coil of wire in a…

    • heated oil
    • pool of water
    • magnetic field

  6. Question 6

    Which statement shows conservation of energy?

    • A ball makes new energy when it bounces
    • A ball has no energy at the top of a throw
    • A ball's lost kinetic energy shows up as heat and sound after it lands

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