BRAINCAKEMaterials
Revision notes for Materials in OCR Physics A (H156). Read the start of any lesson here, then sign in free for the whole lesson, the R.E.C.I.P.E. recall steps and the quiz.
- Tensile and Compressive ForcesEqual and opposite forces that produce extensions are called tensile forces and those that shorten an object are called compressive forces.
- Hooke's LawIf a range of forces are used to extend a spring, it undergoes elastic deformation and the force-extension graph is a straight line through the…
- The Force Constant kIf a spring obeys Hooke's law, the force applied is directly proportional to the extension.
- Investigating Hooke's LawA spring is attached to a clamp which is secured to a bench.
- Elastic Potential EnergyThe energy stored in a stretched or compressed spring is called elastic potential energy and is the area under a force-extension graph.
- Metal Wire DeformationA metal wire obeys Hooke's law until the elastic limit.
- RubberRubber does not obey Hooke's Law.
- PolytheneA polythene strip does not obey Hooke's law.
- Tensile StressTensile stress is defined as force per unit cross-sectional area.
- Tensile StrainTensile strain is defined as extension over original length.
- Stress-Strain GraphMild low-carbon steel is ductile.
- The Young ModulusIf the limit of proportionality is not exceeded then stress ε is directly proportional to strain σ.<.p>The ratio of stress to strain is called the…
- Measuring the Young ModulusThe Young modulus of a wire can be determined by applying a range of loads to it and calculating the extension of the wire.
- More Stress-Strain GraphsA ductile material can be drawn into wires or hammered into sheets(malleable).