Atwood Machine Simulation

Two masses · tension · acceleration · rotation

Mode

Atwood apparatus

Two masses share one inextensible rope over a rotating pulley. Tap each part for its function; drag empty space to pan.

Experiment controls

Left mass

Right mass

Pulley mass

Pulley radius

Axle resistance

Available travel

Ready. Predict the direction, then start.

Simulation speed

Equations and substitution

Camera and focus

Tap a mass, rope, pulley or sensor.

Teacher demonstrations

Voice and language

Language

Narrator

Speaking speed

Narration volume100%

Embedded loudness-normalized audio can be captured when your external recorder includes tab or system audio. No microphone is required.

Ready · 10 teacher-led chapters.

Chapters

Atwood problem method

Choose positive motion toward the heavier mass.
Draw weight and tension on each mass separately.
Use the whole system to calculate acceleration.
Return to each mass equation to calculate tension.
Include pulley inertia and axle resistance when required.

Core equations

Ideal acceleration = 9.81 × (right mass − left mass) ÷ (right mass + left mass)

Solid-pulley model: add half the pulley mass to the denominator.

Left tension = left mass × (9.81 + acceleration)

Right tension = right mass × (9.81 − acceleration)

Angular acceleration = linear acceleration ÷ pulley radius

Velocity history

Investigations

Balance the masses. Keep their difference fixed while increasing both. Increase pulley mass. Add just enough axle resistance to prevent motion. Swap the masses and explain every sign change.

Model boundaries

The rope is inextensible and does not slip. Hanging masses are particles. The pulley is a uniform solid disk. Air resistance and rope mass are omitted; axle resistance is represented by an opposing equivalent force.

Seven-question check

0 / 7

Teacher whiteboard

Switch to Teacher mode to draw.

1 / 10

Pen colorWidth

Place external image

Ten independent pages. Works with touch, stylus, mouse, Android devices and interactive smart boards.