Work Only Counts What Moves Along

You'll learnthat only the force component along the motion does work.

A rope at an angle, a spring that fights back harder the farther it goes, and a force that can run the ledger backward. Work is the integral of force along the path — watch where the joules actually come from, and where they don’t.

8 STEPS · 6 QUICK CHECKS · v2

WORK LAB

Before you start

What you're looking at

A sled on the floor dragged 4 m by a rope pulling 10 N, held at 60° above the horizontal.

The question

How much work does the angled rope actually do on the sled?

Watch for

The rope splitting into a forward piece and an upward piece. Only one moves the sled along.

What the symbols mean

F = 10 N tension, θ = 60°, d = 4 m displacement; the work meter reads joules (J).

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