Stress & Strain Stress Stress is the applied force per unit cross sectional area of a material Forces can be; Tensile forces, which pull on an object and extend it Compressive forces, which pus...
Hooke's Law When a force F is added to the bottom of a vertical metal wire of length L, the wire stretches A material obeys Hooke’s Law if: The extension of the material is directly proportional to...
Core Practical 4: Investigating Viscosity of a Liquid Aim of the Experiment By allowing small spherical objects of known weight to fall through a fluid until they reach terminal velocity, the visco...
Stoke's Law Viscous Drag Viscous drag is defined as the frictional force between an object and a fluid which opposes the the motion between the object and the fluid Viscous drag is calculated using...
Upthrust Archimedes' Principle Archimedes’ principle states: An object submerged in a fluid at rest has an upward buoyancy force (upthrust) equal to the weight of the fluid displaced by the object ...
Density Density is the mass per unit volume of an object Objects made from low-density materials typically have a lower mass For example, a balloon is less dense than a small bar of lead des...
Modelling the Variation of Resistance with Illumination Light can cause a change in conductivity of some semi-conductors When light is absorbed by the material it causes more electrons to be availa...
Modelling the Variation of Resistance with Temperature All materials have some resistance to the flow of charge As free electrons move through a metal wire, they collide with ions which get in thei...
Core Practical 3: Investigating E.M.F. & Internal Resistance Aims of the Experiment The overall aim of the experiment is to investigate the relationship between e.m.f. and internal resistance b...
