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.
The formula for efficiency is: efficiency = (useful energy transferred / energy supplied) x 100. It is important to note that the efficiency of any machine or device will always be less than 100 percent. Continue Reading.