Skip to lesson

Learning Labs / Physics Workshop

Build it. Understand it.

Build small machines, solve workshop missions, and discover the forces behind every move.

Learning path / 6 lessons0 / 6 completed

Lesson 01 / Build your understanding

Levers & turning force

Use force × perpendicular distance to choose an arrangement that lifts a load within a force budget.

01 / Concept

Start with the idea.

A force turns a lever about its pivot. Its turning effect, torque, depends on both the force and the perpendicular distance from the pivot to the force's line of action.

With vertical forces on opposite sides, compare their opposing torques. A longer effort arm lowers the balance force, while a shorter load arm lowers the load torque. An ideal machine trades force for movement distance.

Read the reasoning

Equal opposing torques give no angular acceleration from those forces. The workshop's illustrated lift requires a small extra effort beyond balance; it does not calculate the beam's rotational dynamics.

Key terms
Torque (N·m)
Force × perpendicular moment arm; a turning effect about a chosen pivot.
Mechanical advantage
The ratio of load force to effort force for the ideal arrangement.

02 / Predict

What do you expect?

A 12 kg load sits 1 m left of the pivot. You push down with 40 N at 1.5 m on the right. Which side initially has the greater turning effect?
03 / Experiment → 04 / ExplainChange one thing. See why.

Workshop mission / 01

Lift the workshop crate

Mount the 12 kg crate on the left. Find a lever arrangement that lifts it with no more than 45 N on the right.

BUILD & TEST

Goal: Lift 12 kg · effort ≤ 45 N

Inspect the kit

Preparing your workbench…

Lift the workshop crate. The mission load is waiting in the tray. Mount it with the button or drag it onto the machine. Teal arrows show effort; amber arrows show weight or friction. Numerical measurements below define the model.

Drag empty space to rotate · Scroll or pinch to zoom · Select a part · Arrow keys rotate the focused view · Home resets it. Labeled controls offer the same actions.

117.72 N·mLoad torque
60.00 N·mEffort torque
78.48 NBalance force

Your proposed setup

Measurements update as you build. Run the mission to test the mounted load and check the goal.

F_balance = (12 × 9.81 × 1.00) / 1.50 = 78.48 N
See the labeled force diagramFront diagram of the current workshop setupPIVOT12 kg / drag onto left arm40 N / 1.50 mLOAD MOUNTSame mounting points and directions as the 3D kit; stylized component sizes.
How this model works

A rigid, massless lever with an ideal pivot. Both applied forces act vertically. The threshold is the balance force; a small excess starts a slow lift. The movement illustrates the direction, rather than predicting speed or exact angular acceleration.

Gravity is 9.81 m/s². Model proportions and most movement timing are illustrative. The numerical measurements and mission checks use the displayed equations.

05 / Practice

Put the idea to work.

A 40 N load acts at 0.5 m; a 10 N effort acts at 2 m on the other side. What do the torques do?

06 / Recap

Take the lesson with you.

  • Compare torque, not force alone.
  • Longer effort arms reduce the required effort and increase its movement distance.
  • A balance threshold is not a prediction of motion speed.

Check your prediction and solve a practice challenge to complete this lesson.

References & further reading

Keep your curiosity going.

More Learning Labs

Loading more Learning Labs…