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Hooke’s Law and Young’s Modulus Revision
Define these terms:
• Stress
• Strain
• Extension
• Length
• Compression
• Tension
Hooke’s Law
This is the force applied (N)
This is the extension (m)
We can write it another way
This is the force applied (N)
This is the gradient (N/m) and is unique for each spring
This is the extension of the spring (m)
Young’s Modulus
Elastic Movement in Metals
Atoms are stacked in planes as +ve ions in a sea of -ve free electrons.
When stress is applied to the metal, the +ve ions will start to spread apart.
The atomic bonds stretch, and the attractive forces between the atoms will oppose the applied stress, like millions of tiny springs.
If the metal has not yielded, the interatomic forces will pull the metal back into its original shape when the stress is removed.
Elastic Movement in Metals