Physics · Lesson Worlds

Momentum: interactive science lab

Crash one mass into another and prove that motion is shared, not lost.

Free · No account required · Runs in your browser

What will you learn?

Momentum is mass times speed. In a fair crash it is kept. Equal masses swap. A heavier incoming mass keeps going.

How does the lab work?

Observe the simulation, make a prediction, change a variable, run the experiment, and explain the result. Finish with a challenge that tests your understanding.

You can change: Incoming mass, Target mass, Incoming speed. Compare what happens and connect the result to the scientific explanation.

Try a comparison in Momentum

Start with the lab’s initial settings. Choose one control below, predict the result, and change that control while keeping the others fixed. Record the setting and what you observe before making a second change.

Incoming mass: the lab starts at 1 kg; its available range is 0.5–4 kg.
Target mass: the lab starts at 1 kg; its available range is 0.5–4 kg.
Incoming speed: the lab starts at 4 m/s; its available range is 2–8 m/s.

For a named starting condition, try Equal, Heavy hit, Light hit. A preset can change several settings: check the controls before treating two presets as a one-variable comparison.

Questions to discuss during the activity

Watch what happens. The incoming mass stops. The parked mass takes the speed. Watch equal masses meet.
Name the cause. That amount is momentum. In this elastic crash it is kept. Equal masses trade places. A heavier incoming mass cannot dump all of its motion into a lighter target, so it keeps going. Motion has an amount: mass × speed.
Change something. Make the incoming mass heavier and it should keep moving after the hit. Change the incoming mass, then send it.
Guess before you run. If the incoming mass is much heavier, after the crash it will… Guess what will happen, then run to check.

After your comparison, explain how the observations connect to this idea: Momentum is mass times speed. In a fair crash it is kept. Equal masses swap. A heavier incoming mass keeps going. Name one condition you held fixed and one feature of the real world this model simplifies. A completed run is a starting point for discussion, rather than proof of mastery.

Who is it for?

Curious learners exploring physics. A parent or teacher can help younger learners read the instructions and discuss the results. Choose by topic and prior knowledge rather than a fixed grade level.

Is this lab free?

Yes. This interactive lab is free without signing in or a paid membership.

No app download is needed; interactive play requires JavaScript and a modern browser.

Use this activity with a learner

Families and educators · choose by prior knowledge

Learning goal: Momentum is mass times speed. In a fair crash it is kept. Equal masses swap. A heavier incoming mass keeps going.

Before you begin: Read the controls for Incoming mass, Target mass, Incoming speed. Make one prediction before changing a setting.

Check understanding: Ask for one observation, the evidence that supports it, and a question to investigate next.

A simulation simplifies the real world. Explain which conditions stayed fixed; a successful run alone does not demonstrate mastery.

Investigate motion during a collision: prediction, evidence, and follow-up

Share Momentum with your family or class. No account is needed to open the free resource.

Activity and guide by Lesson Worlds. About the platform.

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