Transcript Energy PowerPoint

Energy
Energy
 Energy
is the ability to do work
 Comes in many forms
 Measured in joules (J)
 Objects can gain energy when work is
being done to them
 Kicking a football
 Lifting an object
Forms of Energy
 Mechanical
– The energy associated
with motion
 Walking or riding a bike
 Water in a waterfall
A
car or a plane
Forms of Energy
 Electromagnetic
charges
 Electricity
 Light
– moving electric
Forms of Energy
 Nuclear
– energy from the nucleus of
an atom
 Nucleus is split - Fission
 Nuclei
join - Fusion
Forms of Energy
– Breaking or making
chemical bonds
 Burning rocket fuel
 Chemical
 Digesting
 Playing
food
a sport
Forms of Energy
– The internal motion of atoms
 The faster particles move, the more
heat energy is produced
 Rubbing hands together – the
friction converts mechanical energy
to heat
 Phase changes – like melting
 Heat
Energy
 Does
a ball have energy?
 Does it have energy when it falls?
 Can energy be created in the ball?
 The
ball had energy before it was
dropped – potential energy
 The ball had energy as it was dropped –
kinetic energy
Kinetic Energy

Potential Energy
Energy – the energy of
position – stored energy
 Potential
 Stretched
rubber band
 The string on a bow before an archer
shoots an arrow
 An object before it is dropped
 Undigested food
Potential Energy

Conservation of Energy
 The
law of conservation of energy
states that energy can be neither
created nor destroyed
 Does this sound familiar?
 One form of energy can be converted
into another - Newtons_Cradle__Incredible_Science.avi
 Why is this important?
Conservation of Energy
 Because
we like roller coasters!
 In order for a roller coaster to work,
energy must be conserved
Conservation of Energy
Ticket Out the Door
 At
which point is kinetic energy the
highest?
Ticket Out the Door
 At
which point is potential energy the
highest?
Conservation of Energy
 Design
a Roller Coaster