Science Fenns K-5Grades K to 5
A marble rolling across a table about to strike a second marble, with a line of three marbles beyond.

Science / All lessons / Forces and Motion

Forces Move Energy

A push can pass energy to another object.

Lesson 15 of 41

Try this first

Before we start

Today’s story

Forces Move Energy

Think about a pool game. The cue ball hits the eight ball and stops. The eight ball rolls away. Something moved from one ball to the other.

That something is energy. A moving object has energy of motion. When it pushes another object, a force acts and energy transfers. The first object slows. The second speeds up.

Today we watch energy hop from one object to the next. Marbles make it easy to see. Here are the steps.

See it

Five steps. Every time.

    Hands on

    Marble Track Collisions

    25 minutes · Do this with a grown-up nearby

    You need

    • Two grooved ruler tracks or a folded paper channel
    • Four marbles
    • Tape
    • Ruler
    • Paper

    Do this

    1. Make a straight track from a folded sheet of paper.
    2. Place three marbles touching in the middle.
    3. Roll a fourth marble into the line from one end.
    4. Watch which marble moves away.
    5. Roll the marble faster, then slower, and compare.
    6. Draw arrows showing where motion went.
    Write or draw: A drawing with arrows and notes for slow, medium and fast rolls.

    Watch for: Does the motion jump to the far marble? Does a faster roll push the far marble farther?

    Safety: Keep marbles on the table and pick up loose ones from the floor.

    Same every time

    Three rules

    Rule 1Energy moves, it is not lost

    It goes to other objects or to heat.

    Rule 2Bigger force, bigger transfer

    A harder hit passes more.

    Rule 3Watch the motion

    The pattern shows the transfer.

    Grandpa Fenn’s notebook

    Say it like a scientist

    energy
    The ability to cause change or make things move.
    transfer
    To pass from one thing to another.
    collision
    When two moving objects hit.
    motion
    Change in an object's position.

    Poppy’s quiz

    Six questions

    Tap an answer. Green means right. You will see why.

    Talk about it

    Say it out loud

    • How do you know energy was transferred?
    • What games with balls or bats at home show energy moving?
    Did you know

    A line of billiard balls can pass motion down the row so only the last one moves, as in a desk toy called Newton's cradle.

    Someone who does this

    A coach teaches players to pass force from a swing to a ball.

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