Transcript Mass Energy

Mass Energy
• E = mc2
• Energy and mass are
equivalent
• C = 3 x 108 m/s.
• C is a big number and its
squared! So even if m is
small, E is big.
• A small mass, converted to
energy, gives a lot of energy!
Example
Electromagnetic
energy
•Light displays properties of both
waves and particles.
•Light is an electromagnetic wave-a
wave created by alternating electric
and magnetic fields.
•“Light” is more than just visible light,
it covers wavelengths from radio thru
Gamma rays
•Light is also a “particle” called a
photon.
•Photons have energy given by E=hν or
E=hc/λ. H is constant, c is the speed of
light , ν is the frequency of light and λ
is the wavelength of the light.
Conservation of Energy
• The principle of
conservation of energy
states that energy
cannot be created or
destroyed. But it can be
converted from one
form to another
• This idea of energy
transformation is at the
heart of energy
generation.
Energy Sources renewable vs nonrewnewable
• Renewable – can’t be
exhausted
• Solar
• Geo-thermal
• Tidal
• Wind
• Hydro
• Non-renewable-can be
exhausted
• Fossil fuels (oil, coal etc)
• Nuclear
How much do we use?
• World energy
consumption
• US energy consumption
How much do we use?
How much do we use?
• Almost 95% of the energy we use comes from
non-renewble energy sources!
• One of these days we will run out, and then
what?
• What are some short and long term answers
to this question?
Fossil fuels
FOSSIL FUELS
• Carbon or hydrocarbons (a compound made of hydrogen
and carbon) found in the earth’s crust
• Formed from the bacterial decay of plant and animal life in
ancient (a few hundred million years ago) seas.
• The decomposing material was covered with mud and
sediment
• This increased the pressure and temperature on the
material and deprived it of oxygen.
• A variety of hydrocarbon molecules are created in solid,
liquid and gas states.
• The gas and liquid could travel through the porous rock and
collect in geological traps (rock features that prevent
further movement of the hydrocarbons).
Petroleum traps