The Thinking Experiment

Half-Atwood Machine Discovery Simulation

Interactive Physics Simulation

Investigate how a hanging mass pulls a block on a table, and how friction can stop or slow the system. Use it to build force diagrams, predict acceleration, and test claims before solving packet and exam-style problems.

Controls

Positive direction: block right, hanging mass down.

Quick Scenarios

Half-Atwood View

Track rope motion, velocity direction, and friction effects in real time.

Acceleration (instant)
--
Acceleration (from rest)
--
Tension
--
Friction Force
--
Net Force
--
Velocity
--
Displacement
--
Time
--

Discovery Prompts (Aligned to Unit 6)

1) Start frictionless to build your reference model

Set friction OFF, start from rest, and compare your measured acceleration to your equation for a two-mass system.

Question: How does increasing mₕ change acceleration when mₜ stays fixed?

2) Add friction and find when motion stops

Turn friction ON and slowly increase μ while masses stay fixed.

Question: At what point does static friction hold the system at rest? Explain with net-force reasoning.

3) Try a packet-style context

Use Packet Style preset, then estimate time to move 2.0 m from rest and compare with the simulation.

Question: Which force changed from the frictionless run, and how did that change acceleration?

4) Analyze an exam-style claim

Give the system an initial velocity opposite the acceleration direction.

Question: Can velocity and acceleration point opposite ways at the same time? Use evidence from the run.

Half-Atwood Model Used Here

Sign convention: right/down is positive.

Treat both masses together as one system. The motion of the system depends on the net external force compared to the total mass of the system.

Friction changes the net external force on the system. When friction is large enough, the system can stay at rest.

Use the simulation to identify which forces are external to the full two-object system, then connect your observations to acceleration.

Gravity is fixed at 10 m/s² to match your Unit 6 exam convention.

Recorded Trials

Capture runs to compare frictionless and friction cases during class discussion.

# mₜ (kg) mₕ (kg) μ a from rest (m/s²) T (N) Result
No trials yet.