energy

1. Energy Basics

2. Energy Makes Everything
Energy Makes Everything
Happen
Happen
 You eat food Food provides the
energy to work
 A car drives Gasoline provides the
power

3. Energy is divided into two types
Energy is divided into two types
Depends on whether the energy is
moving or stored

4. Types of Energy
 Energy that is stored
Potential Energy
 Energy that is moving
Kinetic Energy

5. Examples of Kinetic and
Potential Energy

6. Units of Energy Measurement
Units of Energy Measurement
 British Thermal Unit (BTU)
 Joule (J)

7. BTU
BTU
The amount of heat needed to raise the temperature
The amount of heat needed to raise the temperature
of one pound of water by 1
of one pound of water by 1o
o
F
F
 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

8. 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

9. 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

10. Energy cannot be created or
destroyed
Enery can only be changed from
one form into another form of
energy

11. Some Energy Interconversions
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.

12. Categories of Primary Energy
 Energy Income (Renewable resources)
– resources being continuously regenerated
 Energy Capital (Non-renewable)
– use of such resources permanently reduces
the quantity

13. 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

14. Global Energy Fluxes

15. 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

16. Historical Trends in Energy
Consumption