Parkinson's disease is a progressive nervous system disorder that can cause tremors in the hands and arms, rigid muscles and speech changes such as slurring, according to the Mayo Clinic. â
Electric power law: P = V x I   P = power in watts   Einstein's law: E â¦ = m x cÂ²   E = energy in joules, m = mass in kilograms, and c is the speed of light.
Review the simple mathematical formula for calculating the density of a substance, which is density = mass over volume or d=m/v. To use this formula, you will have to know the mass and the volume of the substance. The mass refers to the gravitational pull on the substance and how much matter it contains.