A force-testing machine contains a rigid L-shaped lever that turns about a fixed pivot. With no test force applied, the weight of the lever and pointer produces a clockwise moment. A small calibration weight is attached on the other side of the pivot. Before each test, a technician slides the calibration weight until the pointer remains at zero.
Explain why the calibration weight is adjusted before the test force is applied.
124 exam-style questions on AQA GCSE Physics 5.4 Moments, levers and gears, covering 5.4 Moments, levers and gears. Each one has a worked solution and a mark scheme showing where the marks go.