Power Lab

Work · energy · time

Mode

Choose a real task

Apparatus

Compare machines

Tap a part for its function. Drag the load to inspect progress; drag empty space to pan.

Task controls

Total moving mass

Vertical rise

Driving force

Travel distance

Task duration

Useful efficiency

Motion profile

Simulation speed

Results & equations

Total task work

Average useful power

Camera & focus

Zoom

No part selected.

Teacher demonstration

Reveal quiz explanations

Voice and language

Language

Narrator

Speaking speed

Narration volume100%

Loudness-normalized embedded audio. For external recording, include this tab's audio or system audio. No microphone is needed. The recorder controls capture and recording level.

Ready — ten teacher-led chapters.

Chapter 1 / 10Part 1 / 4

Chapters

A reliable method

Identify the useful task and the work or energy transferred.
Measure its duration in seconds.
Calculate average power: P = W ÷ t.
Check units and separate useful output from input.

P average = W ÷ t1 W = 1 J/s · 1 kW = 1000 W

Lifting: P average = m × g × h ÷ tEarth: g = 9.81 m/s²

Parallel force: P = F × vMore generally, P = F × v × cos(angle).

Efficiency = P useful ÷ P input × 100%Input = useful output + other energy transfers.

Useful power through the task

Solid line: useful transfer rate. Dashed line: whole-task average.

Learning objectives

Distinguish work and energy from power.
Calculate average and instantaneous power with units.
Predict the effect of mass, force, speed and time.
Explain efficiency without treating energy as lost from existence.

Try, observe, explain

Halve the duration. Does the work change? Double the load while keeping the duration fixed. Explain the new power. Lower efficiency while holding useful output fixed: which input reading increases?

Why can an object have stored energy when its useful transfer rate is zero?

Model boundaries

These are idealized prescribed-motion tasks. Vertical useful work is the gravitational energy gain; conveyor work is force times displacement against resistance. The smooth profile shows the gravitational transfer rate, not the full motor power required for acceleration. Startup kinetic-energy changes, muscle biomechanics, and detailed motor dynamics are not modeled.

Seven-question check

0 / 7