Conservation of Energy IT’S THE LAW

Lifting a Ball When you lift a ball to a certain height you __________________. This work (W) is equal to the weight of the ball (w=mg) _______ the height (h). The work done to lift the ball is stored as ___________________. h W = Fd =wh = _____ PE = W = ____

Lifting a Ball The ball now has potential energy stored in it. This means the ball has the potential to do _______ if you drop it on something. But before it can do that work it must convert the PE to another form of energy called kinetic energy – ______________ h PE = mgh Kinetic Energy Energy of Motion

Kinetic Energy Kinetic Energy (KE) is ________________. Kinetic Energy depends on the moving object’s _____ (m) and the ______ of its _________ (v).

Lifting a Ball As the ball falls: Its Potential Energy _________ because its height ____________. Its Kinetic Energy ________ because it ____________. It turns out the amount of potential energy lost as the ball falls is the _________ as the amount of kinetic energy the ball gains!!!! h PE = mgh Kinetic Energy Energy of Motion

The Law of Conservation of Energy Energy cannot be created nor destroyed, it can just be transformed from one form to another, or transferred from one object to another. If we ignore any losses in energy to sound or heat (two big sources) this means that ___ + ___ will always remain ______________.

A Falling Ball A 2-kg ball falls from a height of 5-m. Trace its PE & KE as it falls. 5-m HeightPE=mghKEME 5-m 4-m 3-m 2-m 1-m 0-m

Pendulums & Roller Coasters Pendulums and Roller Coasters must follow the _______________________________ IT’S THE LAW This means that what ever potential energy is stored in each at the beginning is __________ back and forth between ____ & ____. If we are allowing for losses in energy from heat and sound, then this amount of energy slowly ___________.

A Pendulum

Roller Coasters Roller Coasters use the potential energy stored when it is at the __________ and converts it to _________ throughout the ride.Roller Coasters use the potential energy stored when it is at the __________ and converts it to _________ throughout the ride. WEeeeeeeeee!!!!!!!!!WEeeeeeeeee!!!!!!!!!