Transcript Energy Basics

Energy Basics
Energy Makes Everything
Happen

You eat food Food provides the
energy to work

A car drives
Gasoline provides the
power
Energy is divided into two types
Depends on whether the energy is
moving or stored
Types of Energy

Energy that is stored
Potential Energy

Energy that is moving
Kinetic Energy
Examples of Kinetic and
Potential Energy
Units of Energy Measurement
British Thermal Unit (BTU)
 Joule (J)

BTU
The amount of heat needed to raise the temperature
of one pound of water by 1oF

1 Btu equals about:
– One kitchen match

1000 Btu equals about
– 1 avg candy bar
– 4/5 peanut butter & jelly sandwich

2000 Btu equals about
– the amount of energy to make a pot of
coffee
Joule
948 joules = 1 Btu
 It
takes about 2 million joules to make a
pot of coffee
 1 joule is the amount of energy needed
to lift one pound about 9 inches
Kilojoule (kJ)
1000 j= 1 kJ
A piece of buttered toast contains about 315
kJ of energy. With that energy you could:
 Jog
for 6 min.
 Bicycle for 10 min
 Sleep for 1.5 hrs
 Run a car at 50 mph for 7 seconds
 Light a 60 watt light bulb for 1.5 hrs
Energy cannot be created or
destroyed
Enery can only be changed from
one form into another form of
energy
Some Energy Interconversions




Stored energy in a flashlight’s batteries
becomes light energy when turned on
Food contains energy stored as chemical
potential energy. Your body uses the stored
energy to do work.
Overeating stores food energy as potential
energy in the form of fat
When talking on the phone, your voice is
changed into electrical energy. The phone on
the other end changes the electrical energy
into sound energy.
Categories of Primary Energy
 Energy
Income (Renewable resources)
– resources being continuously regenerated
 Energy
Capital (Non-renewable)
– use of such resources permanently reduces
the quantity
Available Energy Sources
Renewable
–
–
–
–
–
–
–
Hydroelectric energy
Tidal forces
Biomass
Geothermal heat
Wind
Solar input
Ocean thermal
gradients
Non-renewable
–
–
–
–
–
Crude oil
Natural gas
Coal
Nuclear fission
Synthetic oil
Global Energy Fluxes
Primary Energy Consumption
World consumption has increased more
than 10 fold in 20th Century
Causes:
 World population grew 2.5 fold
 Increased mechanization in
industrialized countries
Historical Trends in Energy
Consumption