BRAINCAKEMaterials
Revision notes for Materials in OCR Physics A (H156). Every lesson in BrainCake comes with R.E.C.I.P.E. recall steps, a quick check and spaced reviews.
- Tensile and Compressive ForcesWhen a pair of equal and opposite forces acts on an object, they can change its shape.
- 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 limit of proportionality.
- RubberRubber does not obey Hooke's Law.
- PolytheneA polythene strip does not obey Hooke's law.
- Tensile StressTensile stress σ is the force applied per unit cross-sectional area: σ = F/A, where F is the tensile force and A is the cross-sectional area of the…
- Tensile StrainTensile strain ε is the extension of a sample divided by its original length: ε = x/L, where x is the extension and L is the original length.
- Stress-Strain GraphMild low-carbon steel is ductile.
- The Young ModulusIf the limit of proportionality is not exceeded then stress σ is directly proportional to strain ε.
- 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.
On the specification
- 3.4.1 Springs
- 3.4.2 Mechanical properties of matter