Lesson 9 of 12 · Momentum

Experiment⭐ 30 XP

Rocket Propulsion

🧪Lab Brief #9

Rocket Propulsion.

🎯 Your mission

Set it up. Test it. Be amazed.

⚡ The twist

Nature loves to surprise the careful watcher.

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Mind = Blown

🔬 The more you look, the more nature shows you.

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Make a hypothesis first

Before you start: write down what you think will happen, and why.

What You'll Learn

A rocket carries its own reaction mass. It pushes exhaust gas backwards and, by conservation of momentum, gains forward momentum in return. Because it needs no surrounding air to push against, a rocket works in the vacuum of space.

Key Words

Tap a word to see its definition.

Materials Needed

balloons
drinking straws
string
tape
stopwatch

Safety First

Do not over-inflate: a bursting balloon is loud and its fragments are a choking hazard for younger children.

Steps

Step 1 — Read

Read the explanation above and note the two key terms before you start.

Step 2 — Do

Thread a straw on a long line, tape an inflated balloon to it and release. Time the run for three different balloon sizes and relate the distance travelled to the mass of air expelled.

Step 3 — Observe

Record what actually happened, including anything that did not match what you expected.

Step 4 — Record

Write a conclusion that answers the question this lesson opened with, and state your uncertainty.

Check Your Understanding

Question 1

1 of 2

A rocket works in a vacuum because it:

How sure are you going to be?😐 maybe

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Where you see this in real life

This shows up in your everyday life more than you'd think.

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Stretch Challenge

Try this in real life this week.

Try one experiment in real life this week — even a tiny one.

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For the dinner table

“What's the most surprising thing you learned today?”

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Next Smart Experiment

We'll pick an experiment that matches exactly how you're thinking right now.

🌱Share card

Share this experiment

Send it to a parent who's looking for a 10-minute kitchen science win.

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