A worker pushes two boxes, A and B, across a horizontal floor.
Box A is in contact with box B. The worker pushes box A with a horizontal force of 120 N.
The mass of box A is 20 kg and the mass of box B is 10 kg.
The frictional force on box A is 40 N and the frictional force on box B is 20 N.
Calculate the resultant force on the system of both boxes.
Calculate the acceleration of the boxes.
Calculate the force that box A exerts on box B.
Explain why the force that box B exerts on box A is not included in (a), but must be included in a free body force diagram for box A.
93 exam-style questions on Edexcel GCSE Physics 9.1 Forces and vectors, covering 9.1.1 Interactions and types of force, 9.1.2 Vector and scalar quantities, and 9.1.3 Vector diagrams and free body diagrams. Each one has a worked solution and a mark scheme showing where the marks go.