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Phab Physics

AP Physics 1 · Unit 4 · No account needed

Interactive Unit Review: AP Physics 1 Unit 4

Linear Momentum

This review covers AP Physics 1 Unit 4 at a space station. A 40 kg cargo pod fires a thruster, docks with a 160 kg cargo module, separates from it with a compressed spring, rebounds from a padded bumper, and collides with a drifting crate.

13 questions in 5 stages · progress saves in this browser

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The spring separation stage: a compressed spring pushes the pod and the cargo module apart, with momentum arrows for each body and for the total.
Spring separation · the total momentum stays 600 kg·m/s

How it works

Answer first, then watch your answer run.

You find an impulse from the area under a force graph, use conservation of momentum to find speeds after a collision and a separation, find how much kinetic energy becomes internal energy, find the energy stored in a spring, calculate an average force from a change in momentum, and add momentum vectors in two dimensions. When you answer, the stage runs, and a cyan ghost moves according to your answer beside the real pod.

  1. Answer the question. Each question asks for a number, a choice, a momentum vector diagram, or an energy bar chart. Hints and worked values are available when a step blocks you.
  2. Watch the stage run. The solid objects move according to the ideal solution, and the cyan ghost moves according to your answer.
  3. Read the feedback. Each common mistake gets its own explanation, and the final card lists the topics you missed on the first try.

What this review covers

5 stages from linear momentum.

Stage 1

Thruster launch

  • Impulse from a force–time graph
  • Impulse changes momentum

Stage 2

Docking

  • Momentum is conserved in a perfectly inelastic collision
  • Kinetic energy in a perfectly inelastic collision
  • Energy bar charts for a perfectly inelastic collision

Stage 3

Spring separation

  • Conservation of momentum when objects push apart
  • Energy stored in a spring (Unit 3 review)

Stage 4

Bumper rebound

  • Change in momentum is a vector
  • Average force from impulse
  • Padding and contact time

Stage 5

Glancing collision

  • Momentum is a vector
  • Speed after a two-dimensional collision
  • Direction after a two-dimensional collision

Inside the review

A wrong answer shows what it would do.

The docking stage: a ghost pair moving at the wrong speed after the cargo pod docks with the 160 kg module, beside the real pair.
Docking · the ghost pair moves at the speed you enter
The glancing collision stage: the pod moving east and a crate moving north stick together, with the momentum vectors drawn in the scene.
Glancing collision · momentum adds as vectors

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For teachers

Share one link with your class.

Students do not need accounts. Progress saves in each student’s browser, so a class can finish the review over two periods, and the final card lists the topics each student missed on the first try. Results from this link are not sent to you.

In a Phab Physics class, this review is the Unit Mission at the end of Unit 4, alongside daily handouts, guided problems and practice with a class progress view. See the teacher guide.

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