## Thursday, December 9, 2010

### energy activity sheet

Today in class when we went over the energy Activity Sheet we had for homework. For the first problem The number sentence was 3J +2J=5J. My initial state was You're falling down a mountain(halfway down) and my final state was you're moving really fast at the bottom of the mountain. On my bar chart i had 3J for kinetic energy and 2J for gravitational potential energy (before side) and 5J for kinetic energy on the after side.

The second problem's number sentence was 4J+(-2)=1+1. My initial state was a cart coming toward me and then i pushed it away from me and its about to fall off . My final state was The cart is falling down the mountain about to hit the ground. For my bar chart, i put 4j of energy for gravitational potential energy and -2 work being done(before side). I put 1J for kinetic energy and 1J for gravitational on the after side.

The third problem's number sentence was 200J+800J=500J+500J.My initial state was you jump off a cliff, moving fast,you're 4/5 of the way down.The Final state is you're half way down, moving fast. For my bar chart, i put 200J for kinetic energy and 800j for gravitational potenial energy (before side). Then i put 500J for kinetic energy and 500J for gravitational energy on the after side.
AR

towards the end of class Mr.Finley asked the question why does a pendulum swing back to its original height? Clarie answered that its because nothing does work. She also mentioned that when the pendulum reaches its highest point it has the same amount of energy it started with.