CH. 4 Energy and a little bit of Ch The Nature of Energy 4.2 Conservation of Energy 5.1 Work

4.1 What is energy? Motion needs ____________: Measured in ____________ Energy Types: electrical- _______- radiant-thermal- sound- nuclear – ________________

Potential Energy __________ energy /no motion When a ________________ is pulled back it has ____________ energy ___________ potential energy food ____________ potential energy – Any type of stretched or compressed elastic material Clock ____________ Bungee cord

Gravitational Potential Energy –Apple hanging from a tree –Depends on __________ of objects –Depends on __________ between objects –Grav.PE=mass x ___________ acceleration x height PE=mgh

Kinetic Energy When the apple falls off the tree it has –___________ Energy Depends on ___________(v) Increase in speed results in _____________ ability to do work Kinetic energy =1/2 x ______(kg) x speed squared KE=1/2 m ___ 2

4.2 Conservation of Energy Transforming energy: Light Bulb: ____________  Light  thermal  Gasoline: __________  kinetic motion  electrical  thermal  sound _____________ Energy= potential + kinetic

The Law of Conservation of Energy Energy cannot be created or destroyed, only transformed. Mechanical Energy= K.E. + P.E. K.E.=P.E.

5.1 Work The measure of the _________ over the entire distance covered _____________ Force=Motion Motion=Distance covered Work= ________ x Distanc W= F x d –Joules (ENERGY!!)

Power The measure at the rate at which work is done Power = _______/Time P=W/t –________/Seconds= Watts Power-___________