ELASTICITY NOTES ELASTICITY - The ability of an object to return to its original shape
after a deforming force is removed.
FOUR (4) types of Elasticity:
1. Extension - stretch
2. Compression - squeeze
3. Torsion - twist
4. Flexion - bend
Robert Hooke - In 1678, Robert Hooke studied elasticity. He found
that within the limits of perfect elasticity, strain is directly proportional
to stress. This ratio is known as Hooke’s Law.
Δ (Delta) – The Greek letter for “D” and signifies the change in a value of
a given unit.
STRESS ΔF - The applied force, the weight of the object causing the
spring to stretch. Stress is always measured in units called Newtons (N)
STRAIN ΔL - The change in shape, the amount of stretch measured in
the spring. Stretch is always measured in units of centimeters (cm) or
meters (m)
ELASTIC LIMIT - The point at which too much stress is applied and
the spring will not return to its original shape.
Formulas:
ΔF = K x ΔL
ΔL = ΔF / K
K = ΔF / ΔL
F
K
L