A uniform plank is 4.0 m long and has a weight of 200 N.
The plank rests on a pivot 0.50 m from its left-hand end.
What downward force on the left-hand end will keep the plank balanced horizontally?
67 N67\ \text{N}67 N
200 N200\ \text{N}200 N
1400 N1400\ \text{N}1400 N
600 N600\ \text{N}600 N
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.