How to Produce Heat Energy 
How to Produce Heat Energy
by Prof. Miller
Video Lecture 18 of 46
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Date Added: February 5, 2015

Lecture Description

There are many KINDS of ENERGY: Mechanical - Acoustic - Elec¬tric - Magnetic - Electrostatic - Chemical - Electromagnetic -
Atomic - Nuclear AND HEAT ENERGY. Strangely enough -
ALL of these can be transformed - transmuted - changed - into HEAT ENERGY. Indeed - all forms of energy do end up as heat energy! Physicists therefore refer to heat energy as a "degenerate" form.

A. Acid added to water is an exothermic process. Heat is evolved.
It is interesting to explore just why this occurs!

B. A cold cup of tea can be heated up - as we say - by stirring.
Mechanical energy is transformed into energy of motion of the
tea-stuff.

C. This cold cup of tea can be heated acoustically! Energy is required
for ordinary speech. Some people spend an awful amount of energy
just talking!! It is easy to calculate how much talk would be required to heat this cup of tea: Ordinary talk generates about TOO
ergs per second. This is about one ten-millionth watt.

D. We show an array of simple things:
1. Beat - hit - a sheet of lead with a hammer. It gets hot.
2. Beat a slab of lead with a hammer and a thermocouple imbedded in the lead block would show a rise in temperature.
3. Drive a nail into a block of wood. Pull it out. It is hot.
4. Drill a hard-wood block with an electric drill. The bit gets hot - the shavings get hot.
Here we make reference to Count Rumford - Sir Benjamin Thompson - in the 18th century - who was engaged in the boring of cannon - and his observations are a legacy to our understanding of HEAT.

E. A cardboard tube has some lead-shot in it. Let us first determine
the mass of the shot - the original temperature of the shot - the
length of the tube. Now what can we do? If we invert the tube
end-over-end the shot is now at the top of the tube and under
gravitation it falls down. Work is being done on it by gravitational forces. Its potential energy suffers conversion to kinetic. The impact forces generate heat. Now let us do this operation several
hundred times. We can therefore know the total height through which the shot falls. We can measure its final temperature. We thus can learn the Mechanical Equivalent of Heat. How much work does it take to produce so much heat!
F. Electrostatic energy can produce heat. The apparatus is called an
electrophorus. We rub or slap the lucite slab with a cat's fur.
This work separates the electric charges. We now place atop the
lucite slab a metal plate held by an insulating handle. We ground
the upper face of the metal plate. Now because of Coulomb forces
work is required to lift the plate from the slab. This work or energy
now resides in the form of electrostatic energy. A spark can be
drawn from the plate. This spark represents heat energy and light
energy . We can indeed "light" a fluorescent lamp with the new energy.
Which is an amazing thing indeed! And why is this so? Not certainly because we have a perpetual-motion machine.'.' Never that!
Never! The reason is this: that work is required to lift the plate
free of the charged slab.

G. As an interesting adventure: We show hot to extract a stubborn
glass stopper from a perfume bottle. Friction produces heat!

Course Index

  1. The Idea of the Center of Gravity
  2. Newton's First Law of Motion: Inertia
  3. Newton's Second Law of Motion: The Elevator Problem
  4. Newton's Third Law of Motion: Momentum
  5. Energy and Momentum
  6. Concerning Falling Bodies & Projectiles
  7. The Simple Pendulum and Other Oscillating Things
  8. Adventures with Bernoulli: Bernoulli's Principle
  9. Soap Bubbles and Soap Films
  10. Atmospheric Pressure
  11. Centrifugal Force and Other Strange Matters
  12. The Strange Behavior of Rolling Things
  13. Archimedes' Principle
  14. Pascal's Principle: The Properties of Liquids
  15. Levers, Inclines Planes, Geared-wheels and Other Machines
  16. The Ideas of Heat and Temperature
  17. Thermometric Properties and Processes
  18. How to Produce Heat Energy
  19. Thermal Expansion of Stuff: Solids
  20. Thermal Expansion of Stuff: Gases & Liquids
  21. The Strange Thermal Behavior of Ice and Water
  22. Heat Energy Transfer by Conduction
  23. Heat Energy Transfer by Convection
  24. Heat Energy Transfer by Radiation
  25. Evaporation, Boiling, Freezing: A Dramatic Adventure
  26. Miscellaneous Adventures in Heat
  27. The Drama in Real Cold Stuff: Liquid Nitrogen
  28. The Physics of Toys: Mechanical
  29. The Physics of Toys: Acoustic and Thermal
  30. Waves: Kinds of Properties
  31. Sound Waves: Sources of Sound & Pitch and Frequency
  32. Vibrating Bars and Strings: The Phenomenon of Beats
  33. Resonance: Forced Vibrations
  34. Sounding Pipes
  35. Vibrating Rods and Plates
  36. Miscellaneous Adventures in Sound
  37. Electrostatic Phenomena: Foundations of Electricity
  38. Electrostatic Toys, Part 1
  39. Electrostatic Toys, Part 2
  40. Adventures with Electric Charges
  41. Adventures in Magnetism
  42. Ways to "Produce" Electricity
  43. Properties and Effects of Electric Currents
  44. Adventures in Electromagnetism
  45. Further Adventures in Electromagnetism
  46. Miscellaneous and Wondrous Things in E&M

Course Description

Demonstrations in Physics was an educational science series produced in Australia by ABC Television in 1969. The series was hosted by American scientist Julius Sumner Miller, who demonstrated experiments involving various disciplines in the world of physics. The series was also released in the United States under the title Science Demonstrations.

This program was a series of 45 shows (approximately 15 minutes each) on various topics in physics, organized into 3 units: Mechanics; Heat and Temperature / Toys; and Waves and Sound / Electricity and Magnetism.

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