Some students confuse friction and normal reaction, as both arise from an interaction between an object the surface it is sitting on
More generally, students may confuse Newton's first and third laws because they do not recognise that the forces in an interaction pair always act on different objects, and confuse the balanced forces on a stationary object (such as a box sitting on the floor) with the equal forces of an interaction pair.
Resource that Address This
This resource gives an accessible explanation of friction.View Resource
Friction between solid surfaces (11-16)
Source - Practical physics/ Force and motion/ Friction, turning and other effects
Part 3 explores the idea of normal force.View Resource
Episode 214: Work done by a force (16-19)
Source - TAP/ Work, energy and power
Activity 214-1 explores work done in raising a weight using a ramp. The explanation included both friction and normal force.View Resource
The following studies have documented this misconception:
- Clement, J. () Students' alternative conceptions in mechanics: a coherent system of preconceptions? in H. Helm, and J. D. Novak (Eds), Proceedings of the International Seminar: Misconceptions in Science and Mathematics. Cornell University, Ithaca, NY.