Updated with Electricity and Ohm's Law Notes

1. May 6- May 22
ENERGY

2.  Energy- The ability to do work
 Kinetic Energy- The energy of motion
 Potential Energy- Energy stored as a result of position or shape
 Gravitational Potential Energy- Potential energy that depends
on an object’s height above a reference point
 Elastic Potential Energy- The potential energy of an object that
is stretched or compressed
 Mechanical energy- Energy associated with the motion and
position of everyday objects
 Thermal Energy- The total potential and kinetic energy related
to the motion of all particles in an object
 Chemical Energy- The energy stored in chemical bonds
 Electromagnetic Energy- a form of energy consisting of
changing electric and magnetic fields
 Nuclear Energy- The energy stored in the nuclei of atoms
WHAT IS ENERGY?

3.  In 1845, James Prescott Joule published results from a series
of well constructed experiments and concluded three “laws of
thermodynamics”
 The 1st law of Thermodynamics- Energy cannot be created or
destroyed
 When we observe an energy transformation, all amounts of energy
must be accounted for
 The 2nd law of Thermodynamics- Energy flows from high
concentration to low concentration. (Always from hot objects
to cold objects.
 When we observe an energy transformation, energy is always “lost”
due to things like friction, sound, and heat
 The 3rd law of Thermodynamics- All objects contain some
amount of thermal energy measured on the Kelvin Scale.
Zero degrees Kelvin cannot ever be reached.
 All objects have thermal energy that can be measured and accounted
for
THERMODYNAMICS

4. It is important to recognize our perception of energy
transformation vs. reality of energy transformation.
 Example, touch your table top with one hand and the metal
bar with the other hand. Which surface is colder?
 Both surfaces are the same temperature, why does one FEEL colder?
 You rub your hands together and they get warm?
 You eat a good breakfast before you take your final exams?
 You start your car and drive to the store?
 You flip on the lights when you walk into class?
 You create a camp fire to roast marshmallows?
 The alternator in your car uses the movement of your car’s
engine to charge the battery?
ENERGY TRANSFORMATION

5. HALF PIPE SCIENCE
Kinetic Energy =
Potential Energy =

6. HALF PIPE SCIENCE
Kinetic Energy =
Potential Energy =

7. HALF PIPE SCIENCE
Kinetic Energy =
Potential Energy =

8. HALF PIPE SCIENCE
Kinetic Energy =
Potential Energy =

9. HALF PIPE SCIENCE
Kinetic Energy =
Potential Energy =

10.  Electricity- The flow of electrons in a sample
 Conductor- Physical property of matter which allows electrons to
move freely through it.
 Insulator- Physical property of matter which does not allow
electrons to move freely through it.
 Electric current- The rate at which charge passes a given point
 The rate of flow of electrons in a sample is its current
 The unit for current is “Ampere” (A), called amp for short
 Voltage- The difference in energy per unit charge as a charge
moves between two points in the path of a current.
 The unit for voltage is the “Volt” (V)
 Resistance- The opposition to the flow of electric charge
 The unit for resistance is the “ohm” (R, or Ω)
 Can be thought of as “Electrical Friction”
ELECTRICITY

11.  Georg Ohm discovered that current, voltage, and resistance
are all interrelated. He hypothesized that…
 Amperes (A) = volts (V) / ohms (Ω)
 I (current) = V / R
OHM’S LAW

12.  Electric Power- the rate at which electrical energy is used to
do work.
 The unit for electrical power is “Watt” (W)
 Power = Voltage x Current (P=VxI)
ELECTRIC POWER

13.  Electrical Energy- a measurement of power used with the time
that it is used
 The unit is Kilowatt-hour (KWH)
 Electrical Energy = power (kW) x time (h)
 KWH = kW x h
ELECTRICAL ENERGY