Do Dimensional Analysis.

Dimensional analysis helps you to check your formula derivation.  All terms in the equation should have the same dimension ( or units)

Example: The pressure p is defined as the force F per unit area A.  Suppose you measure force in Newton N and length in m. What is the unit of pressure?


P = F/A. Since the dimension of A is length2.  Thus pressure is measured in N/m2 .

Example: Which of the following formula has correct dimension?

v is the velocity measured in m/s, x is the position measured in m and a is the acceleration measured in m/s2. 


Answer: v = x / t.