Energy Two types of energy: Kinetic Energy Potential Energy The ability of a system to do work. Two types of energy: Kinetic Energy Potential Energy

Energy Transfer Energy TRANSFER is the passing of energy from one object to another object. Example: A cup of hot coffee has thermal energy. Some of this thermal energy is transferred to the particles in cold milk, in which you put to make the coffee cooler.

Energy Transformation-- when energy is changed from one form to another An objects energy can be: As velocity kinetic energy and potential energy As velocity kinetic energy and potential energy 1. All Kinetic Energy 2. All Potential Energy 3. A combination of both increases increases decreases decreases decreases increases INVERSE WHAT IS THE TYPE OF RELATIONSHIP KE AND PE HAVE?

Roller Coasters As you move up to the first hill on a roller coaster the distance between the coaster and the Earth increases, resulting in an increase of Gravitational Potential Energy. At the top of the first hill you have the most Gravitational Potential Energy As you begin your trip down the hill you increase your speed resulting in a transformation from GPE to KE. At the bottom of the hill right before it goes back upward the GPE is small, but the KE is Large. As it starts to move up the next hill or loop KE is transformed back into GPE http://www.youtube.com/watch?v=8abzpXCjyjA

As a basketball player throws the ball into the air, various energy conversions take place.

AC Calculating Ke and Pe

Kinetic Energy – what does it depend on? The an object moves, the it has. The greater the of a moving object, the it has. Kinetic energy depends on both faster more kinetic energy mass more kinetic energy mass and velocity. K.E. = 1/2 m v2.

Calculating Potential Energy OR you could multiply weight (in Newton’s) by height Pe= H x W

1. You serve a volleyball with a mass of 2. 1 kg 1. You serve a volleyball with a mass of 2.1 kg. The ball leaves your hand with a speed of 30 m/s. The ball has ___________ energy. Calculate it. Kinetic Energy K.E. = 1/2 m v2. ½ of 2.1kg x (30m/s)2 1.05 x 900 =945joules

2. A baby carriage is sitting at the top of a hill that is 21 m high 2. A baby carriage is sitting at the top of a hill that is 21 m high. The carriage with the baby weighs 12 N. The carriage has ____________ energy. Calculate it. Potential Energy Pe= HxW Pe 21m x 12N= 252 Joules