Physics - Materials 4.0 / 5 based on 1 rating ? PhysicsMaterialsASAQA Created by: OliviaCreated on: 18-04-13 09:27 Limit of Proportionality When a material will not return to its original shape (eg overstretched spring) 1 of 33 Theory says that if a load is applied to a spring it follows... F=k L up to the limit of proportionality 2 of 33 Hooke's Law is... F=k L 3 of 33 Springs- extension is proportional to... the load 4 of 33 Steepness of graph line = stiffness of spring 5 of 33 Units for k = Nm-1 6 of 33 Homogenous If both sides of an equation have the same units 7 of 33 Area under a line graph with Force plotted against the extension equals... the elastic potential energy of the spring 8 of 33 2 springs in parallel = k= (k1 + k2) 9 of 33 2 springs in series = 1/kE = 1/k1 + 1/k2 10 of 33 Adding a load to a spring places spring under... tension 11 of 33 Compression force tries to push things together 12 of 33 Tensile force tries to push things apart 13 of 33 As the spring gets longer... individual coils of the spring separate 14 of 33 Energy = 1/2 F L 15 of 33 In a wire there are metallic bonds between... adjacent atoms 16 of 33 When a wire is under tension the bonds... lengthen and the atoms move slightly further apart 17 of 33 Remove the tension on a wire and the bonds... revert back to their original length 18 of 33 If we exceed the elastic limit of a wire... the adjacent layers of atoms begin to slide past each other. Old bonds break, a layer slips and new bonds form. 19 of 33 When a wire does not revert to original length this is called... Plastic Flow 20 of 33 Rubber is made of... a long chain polymer 21 of 33 Each molecule of rubber is... normally curled up and entangled with other molecules 22 of 33 Tensile forces acting on rubber... begin to straighten out the tangled molecules 23 of 33 The area between the loading and unloading line on a graph of rubber being stretched... equals the energy lost 24 of 33 Polythene is... a synthetic polymer 25 of 33 Polythene has... strong bonds within each polymer chain 26 of 33 Polythene has weak bonds of cross links between... adjacent chains 27 of 33 Apply tension to Polythene... and the weak bonds break with new links forming easily 28 of 33 In polythene permanent deformation occurs... quickly! 29 of 33 Strain does not have a unit as it is a ... Ratio! 30 of 33 force extension graph of a wire/ spring . 31 of 33 force extension graph of Rubber . 32 of 33 force extension graph of Polythene . 33 of 33
Comments
No comments have yet been made