A-LEVEL PHYSICS: 4.7.6: Energy Conservation (SaveMyExams) Flashcards
What happens when a Metal Wire is loaded with a Force & Stretched beyond its Limit of Proportionality?
What happens when the Force is removed?
It will Undergo Plastic Deformation.
The Wire is unloaded, causing the Extension to Decrease.
Explain the features of the Force-Extension Graph of a material that has undergone Plastic Deformation: (3)
-the Unloading Line is Parallel to the Loading Line (since k is Constant)
-the Unloading Line does not go through the Origin (since there is still some Extension after Unloading the Force)
-the Area between the Loading & Unloading Lines represents the Work Done to permanently deform the wire
The Force-Extension Graph for a material may not always be the same when ___ & ___.
Loading, Unloading
Explain the features of the Force-Extension Graph for Stretching & Contracting a Rubber Band: (5)
-Loading & Unloading Curves (curves up & down respectively)
-Unloading (Contraction) Curve also goes through the Origin (since there is no Extension once Force is removed)
-Area between the 2 Curves: Work Done in Heating the Rubber
-Area Under Unloading Curve: Work Done in Stretching the rubber band
-Total Area Under Loading Curve: Total Work Done
Overall, what does the Force-Extension Graph for Stretching & Contracting a Rubber Band show?
The Graph shows that the Rubber Band Stores a Greater amount of Strain Energy when it is Loaded (Stretched) than when it being Unloaded (Contracted).
A Rubber Band becomes warm when it is Stretched and Contracted hence…
some Energy is Transferred to Heat Energy.
Vehicle suspension systems are made up of: (3)
-Tires
-Springs
-Shock Absorbers
Explain ‘car suspension Shock Absorbers’:
-Elastic Object
-designed to Absorb Impact
When a vehicle hits a bump in a road, the Shock Absorbers dampen the Movement of the Springs in the Suspension System. How?
By Converting Kinetic Energy, from the Movement of the Car, to Thermal Energy, which is Dissipated.
