Predict first: will the motor lift it? Then hold LIFT or use Auto lift. Pause whenever you want to compare the rope markers and the cargo.

A fixed pulley changes direction. Two supporting rope sections halve the pulling force, but need twice the rope travel. Four sections need one quarter of the force and four times the travel. The cargo’s weight never changes. Count the sections supporting the moving block, not all the pulley wheels.

For your online class: students vote on a rig, explain their prediction, then test it together. Ask: “What stayed the same?” “What moved farther?” “Why isn’t the 4× rig always the best choice?”

Touch or mouse: drag cargo onto the crane, or tap its card. Keyboard: Tab to choose cargo and a rig. Hold Space or Enter on LIFT, or use Auto lift. Changing the cargo, rig, or height resets the lift.

This is an ideal, frictionless model with a massless lifting platform. The cargo weights are invented for comparison. The same 6-newton motor pulls rope at the same speed in every setup. The rope budget is how much rope the winch can pull during a lift, not the total length used to thread the pulleys.