Physics Equations “Solids” - MCAT

Solids — Included for completeness; DO NOT LEARN THESE! [according to Shrike]

Stress = (Force) / (area) — Stress is what is done to an object
**The maximum stress applied to an object that allows the object to regain its original dimensions is called the yield point — beyond this point, an object will not regain its shape**

Strain is the fractional change in the objects shape
**it equals the (change in dimension) / (original dimension)**

Always note that stress is proportional to strain:

The modulus of elasticity for a certain objects = (stress) / (strain)

Young’s Modulus - deals with length changes in objects with an applied force
**F = (Y)(change in length)(Area) / (Original Length)**

Shear Modulus — deals with shear deformation of objects with an applied force
**F = (S)(amount of shear)(Area) / (original length)**

Bulk Modulus — deals with volume changes of objects by an applied pressure
** P = (-B)(change in volume) / (original volume)**
**Note that the negative sign denotes that anytime there is an increase in pressure, there is a decrease on volume**