So today there were another couple of equations, both of them for calculating the amount of energy something has. The units are Joules (J) Kinetic energy or E(k) is working out how much energy a moving object has. Potential energy is how much energy is stored in a high object – like the energy in the water of a dam, or something lifted off the earth.Potential energy is E(p)=m.g.h So the higher you lift something the more energy it has. The larger the object you lift the more energy it has. g is for gravity, which remains a constant on this earth and you will be told g=10m.s-2. Try it with some simple numbers eg m=4g, g=10m.s-2, and h=12m, and then double the mass to 8g. Try doubling the height to 24m… When they went to the moon gravity was less. But imagine (or calculate) the effect of going to Jupiter where gravity =40m.s-2 The homework was to finish the question given in class and do Question Four of page 81 in your green book…The class question was: A metal weight (2700g) in the gymnasium was left on a shelf 2m above the floor. It falls. It takes 0.8secs to fall (me bad, thanks for noticing Gavin)How much energy did it have on the shelf?How fast was it going when it hit the ground?What was its acceleration?With what force did it hit the ground?
21 July Calculating Energy, kinetic and potential
HOW DO YOU WORK OUT TIME??? IM CONFUSED ON QUESTION 2 FROM THE BOARD IN TODAYS LESSON THAT WE WERE SUPPOSED TO DO FOR HOMEWORK
Oh, you’re right, you need to be given the time.
I’ll make it 0.8 seconds.