KINETIC ENERGY
• Kinetic Energy (KE) - the energy that a body has because of is motion 
          KE = (1/2)*m*v²            [m = mass, v = velocity]
• According to the work-energy theorum, the work done on an object by the net force acting on it is equal to the change in KE of the body. 
         W_net = KE_f  - KE_i = (1/2)*m*v_f² - (1/2)*m*v_i²

POTENTIAL ENERGY
• Potential Energy (PE) - the ability of a body to do work because of its position, shape, or form
• Gravitational PE depends upon the weight of the body and its separation from the Earth 
           PE_g = mgh            [m = mass, g = gravitational acceleration, h = height] 
      or PE_g = (weight)(height) 
• Potential energy can be put into a spring by stretching or compressing it by x amount.
         PE_elastic = (1/2) kx²

CONSERVATION OF ENERGY
• In a system where no energy is lost, and PE changes to KE and KE changes to PE, then we can say that the sum of the KE and the PE is the total energy, and is constant. 
          PE + KE = total E = constant 
• That constant amount (of total energy in the system) is called the mechanical energy.
• ME_i = ME_f
• For an object moving vertically (dropped or thrown straight up): 
          At the top: PE = maximum and KE = 0. 
          At the bottom: PE = 0 and KE = maximum. 
• The maximum equals: PE at the top, KE at the bottom, and PE+KE anywhere in-between. 
• So you could say, at any point in between, PE + KE = a constant equal to the PE of the top or KE of the bottom
• You can combine the KE of the bottom and the PE of the top into the following equation.
       (1/2)*m*v_f² = mgh      >        v_f² = 2gh

^POWER
• Power is the rate at which work is done.  It is calculated by the formula:   P = W/t 
• It can also be found by the force times the speed.  P = Fv
• The unit for power is the watt.  [1 watt = 1 joule / sec] 
• Since a watt is so small, power is often measured in kilowatts (1 kw = 1000 watts). 

ENERGY
• Energy is the ability to do work. 
• The units for energy are joules (same as work). 
• Energy conservation - when energy is transferred or converted, no energy is lost and no new energy is created 

• Energy can be changed from one form to another, but it cannot be destroyed. 
• Matter can be changed from one form to another, but mass cannot be created or destroyed. 
• The combined quantity of mass and energy in the universe remains constant. 
• Energy can be changed into mass, and mass into energy, by Einstein's equation. 
                E = m*c²          [E = energy, m = mass, c = speed of light]