Unit 8: Work, Energy, and Power

            Today in class we began unit 8 about Work and energy. Work is a scalar quantity, which means that it doesn't have direction. Work is any change in energy and I expressed in a equation like this, work= force • change in direction. The unit for work is a Joule, not a jewel like a diamond, but the word joule. In order to do work you actually have to move somewhere. Even if you are lifting something heavy but you are not moving anywhere you aren’t doing work. We also learned about the law of Conservation of Energy. It basically states that energy cannot be created nor destroyed, it can only change forms. So Ein=Eout.We learned about three different types of energy, gravitation energy, or the energy an object has due to its postion in a gravitation field ( Peg= mass*gravity*position/height), Kinetic energy, or energy in motion (KE= ½ mass • velocity², and spring potential energy (PEs= ½ spring constant (N/m) •distance². Hookes law is Fs=kd. We also learned that power is the rate at which work is done. The units for power are watts. 

           In this picture my friends and I are all carrying tons of books and bags so we think we are doing work but really we aren't. Because my friends and I aren't moving anywhere we are technically doing "work" in a physics world. But if we walked 3m while carrying all of that we would be doing work!