Work, Energy and the Conservation of Energy
Work is any change in energy.
Formula for work: Force x Distance
Units: Newton x meter = Joule
Conservation of Energy: in an isolated system, energy will be conserved. (Total Ein = Total Eout)
Gravitational Potential Energy: energy given to an object in a gravity field/ energy's position in gravity. (mass x gravity x height)
Kinetic Energy: energy of motion (1/2 mass x velocity^2)
Power: rate at which work is being done. (change in energy/ change in time) (units: watt)
In the example above, it shows a pillow being kicked off a flight of stairs, what exactly is happening in this system? Well, my sister (person kicking the pillow) is applying energy to the pillow thus giving it energy. See what's happening is the energy being applied to the pillow is being taken from my sister. The work of the pillow will be determined by the force applied to the pillow along with the distance it traveled. Now, when the pillow left the ground and started to fly down the stairs it gained something called gravitational potential energy, or energy of position, which is the pillows position in gravity. Now while the pillow travels down to its destination is gains something called kinetic energy, which is the energy of the motion, and it loses potential energy. The rate at which all of this is being done is called power.
