1. POTENTIAL ENERGY & WEIGHT NOTES Nov 10 Copy everything in the black font

2. ENERGY The ability of an object to do work is energy. Everything in the universe is either matter or energy.  Matter: anything that has mass and takes up space (made of atoms)  Energy: everything else  HeatLightSoundElectricity  ChemicalRadioactive

3. ENERGY 2 types of Mechanical energy  Potential energy – energy due to position  Kinetic Energy – energy due to motion

4. PRACTICE PROBLEMS 1. What 4 types of energy make up an explosion from a nuclear bomb? 2. Are the seismic waves from an earthquake matter or energy? 3. Is the atmosphere matter or energy? 4. A ball at the top of a ramp has _____________ energy and when rolling across the floor it has _____________ energy.

5. POTENTIAL ENERGY (PE) Depends on an object’s weight and position. Weight (N) = mass(kg) x gravity(m/s/s) Gravity? 9.8m/s/s on Earth

6. POUNDS TO KILOGRAMS Weight in Pounds ÷ 2.2 converts to kilograms Ex: 195lbs ÷ 2.2 = 88.6kg

7. PRACTICE PROBLEMS 5. Convert your weight in pounds into kilograms to get your mass. 6. What is your weight in Newton’s on earth? 7. On the moon acceleration from gravity is 1.62m/s/s. What is your weight in Newton’s on the moon? 8. On the sun, gravity is 274m/s/s. What is your weight in Newton’s on the sun?

8. POTENTIAL ENERGY (PE) – UNITS OF JOULES Gravitational PE = weight x height GPE = mgh For any two objects at the same relative height, the heavier object has more potential energy. m g h

9. THE ROUTE AN OBJECT TAKES HAS NO EFFECT ON PE.

10. WHAT KIND OF ENERGY?

11. PRACTICE PROBLEMS 9. An airplane cruises at 9000m above the ground. It has a mass of 850,000kg. What is its potential energy? 10. If you are on top of a 2 story building which is 4.5m high, what is your potential energy? 11. At the top of the 25m hill a roller coaster with a mass of 1000kg has how much potential energy? 12. When the roller coaster reaches the bottom of the hill, does it have any potential energy? Explain.