Brandon Dolly

1
ENERGY

• Brandon Dolly

2
Energy States

• Energy can be found as in two forms, Kinetic and
  Potential. Kinetic energy is energy of motion
  and Potential energy is energy that can be stored
  until it becomes kinetic energy.
• Students are asked to think of examples of each
  form of energy
• Energy can be found as light, heat, chemical,
  mechanical, atomic, sound, electrical

An example of potential energy changing into
kinetic energy
3
Laws of Thermodynamics

• 1st Law Energy can neither be created or
  destroyed.
• We discuss the implications of this such as the
  prospect that there is as much energy now as
  there was at the beginning of the universe.
• This includes thinking about all processes
  converting forms of energy. The students should
  learn that energy is never used up.
• 2nd Law Any time energy is converted from one
  form to another, the universe becomes more
  random. For younger students I simply introduce
  this by saying that any conversion results in
  some energy being lost as heat.
• We discuss examples of the second law such as the
  temperature of tires after a car ride.
• I introduce entropy to older students. Entropy
  is a measure of the randomization in the
  universe. The 2nd law can now be restated. I
  use an example to demonstrate why it is more
  probable for a situation to become more random
  than more organized. I also help them understand
  this principle by explaining the theory of total
  heat death.

4
Work and Energy Dimensions Force x Length

• Joule (J or Newton-Meter) Energy required to
  lift one kg of water one meter.
• Foot-Pounds (ft-lbs) Work required to lift one
  pound of flesh 1 foot. 1 ft-lb1.3 J
• Calorie (Cal). 1 Cal4185 J3087 ft-lbs

Crude Oil 1.5x108 Joules/Gallon
Capn Crunch 6.4x106 Joules/Gallon
5
Some energies

• Aircraft carrier at 30 knots 4.8x109J (1 million
  Calories)
• Dbl Cheese Burger, XL fries Choc. Shake 107J
  (2,530 Cal)
• Adult Daily food intake 8.4x106J (2,000
  Calories)
• Cat Daily food intake 1.4x106 J (350 Calories)
• Average car going 100 kmph 2x105 J (50 Calories)
• 200-lb linebacker in a full run 2600 J (0.6
  Calories)
• Speeding Bullet (900mps) 1600 J (0.4 Calories)
• Baseball pitch (90 MPH) 110 J (0.02 Calories)
• 35 gram arrow going at 55mps 55 J (0.01 Calories)

6
1st Law of Thermodynamics

• I Emphasize the first law of thermodynamics, that
  energy can neither be created or destroyed.
• I explore with students energy transfer through
  fun mechanisms
• I will give each student a copy of a couple of
  Rube Goldbergs comics and briefly discuss the
  energy transfer involved.
• I then set up the board game Mousetrap and let
  the students take turns setting it off
• We discuss how the mouse trap demonstrates the
  1st law of thermodynamics

7
Sample Mechanisms

• Open window (A) and fly kite (B).  String (C)
  lifts small door (D) allowing moths (E) to escape
  and eat red flannel shirt (F).   As weight of
  shirt becomes less, shoe (G) steps on switch (H)
  which heats electric iron (I) and burns hole in
  pants (J).   Smoke (K) enters hole in tree (L),
  smoking out opossum (M) which jumps into basket
  (N), pulling rope (O) and lifting cage (P),
  allowing woodpecker (Q) to chew wood from pencil
  (R), exposing lead.  Emergency knife (S) is
  always handy in case opossum or the woodpecker
  gets sick and can't work.
• This is a fun mechanism as is the one used in
  mousetrap. Mechanisms are a good way to
  demonstrate the 1st law of thermodynamics. They
  are widely applicable. Energy transfer is a key
  to understanding mechanisms in advanced sciences
  such as biology, chemistry, and physics.

8
Upper Level Students

• The focus of this presentation is understanding
  the first law of thermodynamics. This is a
  widely applicable law. For students who have
  already been introduced to this idea, I can
  discuss applications of the law using specialized
  mechanisms such asorganic chemistry examples,
  energy of catalysts, and the electron transfer
  chain of cellular respiration. Teachers of upper
  level classes should contact me prior. This
  presentation can be tailored to a class depending
  on the students knowledge.