A student uses a long screwdriver as a lever to open the lid of a tin of paint. The edge of the tin acts as the pivot.
The student pushes down on the handle with a force of 20 N. The handle is 0.25 m from the pivot.
The tip of the screwdriver is under the lid, 0.010 m from the pivot.
Use the equation: moment of a force=force×distance\text{moment of a force} = \text{force} \times \text{distance}moment of a force=force×distance
Calculate the moment of the student's force about the pivot.
Calculate the force the tip of the screwdriver exerts on the lid.
Explain how the screwdriver acts as a force multiplier.
A force of 500 N on the lid is needed to open the tin.
The student now pushes on the handle at 0.15 m from the pivot.
Calculate the force the student must now apply to open the tin.
46 exam-style questions on OCR GCSE Physics 2.3 Forces in action, covering 2.3.1 Stretching, bending and compressing, 2.3.2 Elastic and plastic deformation, 2.3.3 Force and extension of a spring, 2.3.4 Linear and non-linear force-extension behaviour, 2.3.5 The spring constant, 2.3.6 Work done in stretching, 2.3.7 Gravitational fields, 2.3.8 Weight and gravitational field strength, 2.3.9 Acceleration in free fall, 2.3.10 Relating force, mass and gravitational field strength, 2.3.11 Forces causing rotation, 2.3.12 The moment of a force, 2.3.13 Levers and gears, 2.3.14 Pressure in fluids, and 2.3.15 Pressure, force and contact area. Each one has a worked solution and a mark scheme showing where the marks go.