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Science Launch G4 / Week 03 / Wednesday
3/6
Week 03 · Energy on the Move

Wednesday

Investigation: Dancing rice
// Sound, light, heat and electric currents carry energy
⏱ about 15 min

Wednesday: Dancing rice

Rocket stretches plastic wrap over a bowl until it is tight like a drum. He sprinkles a few grains of rice on top.

"Watch this," he says. He bangs a metal pot with a wooden spoon right beside the bowl. Bong!

The rice hops! Raven gasps. "Nobody touched the bowl. What do you notice?"

Nova hovers near the pot. "Here is a clue," she says. "Something traveled from the pot to the bowl. It went through the air."

What you need

  • A bowl
  • Plastic wrap
  • A rubber band big enough to go around the bowl
  • About ten grains of dry rice
  • A metal pot or baking pan
  • A wooden spoon
Safety first
Rice is for science today, not for eating. Nothing goes in your mouth.
Bang the pot gently first. Cover your ears if it gets loud.
Ask a grown-up which pot you may use.

Steps

  1. Stretch plastic wrap tightly over the bowl.
  2. Put the rubber band around the bowl to hold the wrap tight.
  3. Sprinkle about ten grains of rice on the wrap.
  4. Hold the pot close to the bowl, but do not let it touch.
  5. Tap the pot gently with the spoon. Watch the rice.
  6. Now bang the pot a little harder. Watch again.
MAKE A PREDICTION
  • Read the question.
  • Tap your answer.
What will the rice do when you bang the pot harder?
How hard you hit the potWhat the rice did
Gentle tap
Harder bang
The pot made the air vibrate. The energy traveled to the bowl as ____.
Did anyone touch the bowl? Write yes or no.

Sound you can see

The pot vibrated. It made the air vibrate. The air made the plastic wrap vibrate.

The shaking wrap made the rice jump.

That chain shows sound carrying energy from one place to another.

THE DANCING RICE CHAIN
  • ?The spoon hits the pot.
  • ?The pot vibrates.
  • ?The air vibrates.
  • ?The plastic wrap vibrates.
  • ?The rice jumps.
WHY THIS EXERCISESound energy passed from the pot through the air to the wrap and the rice.
RICE DRUM THINKING
  • Read the question.
  • Tap your answer.
Why did we hold the pot close but not touching?
StatementTrue or false?
Sound can travel through air.?
The rice jumped because someone touched the bowl.?
The plastic wrap vibrated before the rice jumped.?
WHY THIS EXERCISESound carried energy through the air to the wrap, and the wrap moved the rice.
What did the pot do first when the spoon hit it? Type one word.
WHY THIS EXERCISEThe pot vibrated, and that started the chain.

You made sound energy visible today! Tomorrow we follow light and heat.

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