Work done by variable force (graphical method)
Work and energy · Physics
Simple pendulum
Interactive 3DRelease the bob and watch true small-angle SHM. The period depends only on the string length.
Controls
Drag the sliders or type a value — the simulation updates live.
m
0.3m2m
°
5°45°
Study notes
A child pulls a sled with a force that increases uniformly from 0 N to 10 N while the sled moves 5 m. Find the work done. Step 1: Draw the F‑x graph. It is a straight line from (0 m, 0 N) to (5 m, 10 N). Step 2: The area under the line is a triangle. Step 3: Area = ½ × base × height = ½ × 5 m × 10 N = 25 N·m. Step 4: 1 N·m = 1 joule, so work = 25 J. Therefore, the child does 25 joules of work on the sled.