Hooke’s law
● ***∆ F=k (¿ stiffness∗of object with elasticity[ N m−1 ]) × ∆ x (extension)
● Force-extension graph
●
k
● 2 springs in series: (∆X = 𝚺∆x) ∆F = K∆X = K(2∆x), K = (doubled extension)
2
∆x
``` parallel: (K = 𝚺k) ∆F = K∆X = (2k)∆X, ∆X = (halved extension)
2
Elastic strain energy
1 1 2
● *** Eel = F ∆ x= k x
2 2
Stress, strain & Young modulus
● Tensile - pull, compressive - compression
1