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Science Launch G4 / Week 02 / Wednesday
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Week 02 · Crash Test

Wednesday

Investigation: Marble crash test
// Where energy goes when things collide
⏱ about 15 min

Wednesday: Marble crash test

Rocket lays two rulers side by side on the floor, leaving a skinny gap between them. "A marble track!" he says.

He sets one marble in the track and flicks another marble at it. Click! The first marble shoots away.

Raven leans in. "Let's do that again, slowly and carefully. What do you notice about each marble?"

Nova lights up the track. "Would you like a hint? Watch the moving marble right after the click."

What you need

  • Two rulers the same length
  • Tape
  • Three marbles the same size
  • A short ramp, like a hardcover book propped on another book
  • A ruler or tape measure for measuring
Safety first
Keep marbles away from little brothers and sisters.
Nothing goes in your mouth.
Pick up every marble when you finish so nobody slips.

Steps

  1. Tape the two rulers side by side with a small gap. This is your track.
  2. Lean the book at one end of the track to make a short ramp.
  3. Place one marble on the track, two finger widths from the ramp. This is the target.
  4. Let a second marble roll down from halfway up the ramp.
  5. Watch both marbles. Listen to the click. Measure how far the target rolls.
  6. Now let the marble roll from the very top of the ramp. Measure again.
MAKE A PREDICTION
  • Read the question.
  • Tap your answer.
The rolling marble hits the still target marble. What will the target do?
Which start will make the target roll farther?
Start spotHow far the target rolled (cm)Click: soft or loud?
Halfway up
Very top
After the click, did the rolling marble speed up or slow down?
WHY THIS EXERCISEThe rolling marble gave energy away to the target, so it slowed down.

Look at your results

Compare the two rows in your table.

The marble from the very top was moving faster when it hit the target.

A faster marble brings more energy to the crash. So the target should roll farther.

CRASH THINKING
  • Read the question.
  • Tap your answer.
Why did we use marbles that are the same size?
The click was louder from the top. What does that tell you?
The marble that was hit is called the ____.
The rolling marble gave its energy ____.

You ran a crash test like a real engineer! Tomorrow we compare fast and slow crashes.

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