The Ideas of Heat and Temperature 
The Ideas of Heat and Temperature
by Prof. Miller
Video Lecture 16 of 46
Not yet rated
Views: 1,223
Date Added: February 5, 2015

Lecture Description

It is absolutely essential that we UNDERSTAND these IDEAS - that the MEANING of the terms be "loud and clear" - and so we show an array of DEMONSTRATIONS to distinguish the commonplace notions of HEAT and TEMPERATURE.

A. In the very first demonstration we show a sealed glass tube containing a bit of mercury and some tiny glass chips. We heat the tube
gently. The MOTION of the STUFF increases. Some of the mercury is vaporized - since the tube was somewhat pumped down before sealing - and the mercury vapor PUSHES the glass chips into
great agitation. The higher the TEMPERATURE the greater the agitation. As the system cools down - as we say - the system gets
quieter and quieter. HEAT|SA~M0DE OF MOTION. (You will
observe that when I represent the addition of HEAT ENERGY to a
system I show a candle flame. This is a tribute to Michael Faraday
who gave six one-hour lectures on a CANDLE.) The phrase HEAT
IS A MODE OF MOTION was first advanced by one of the BERNOULLI family - that family of one hundred or more geniuses!

B. We heat an array of various spheres of stuff in a beaker of water.
After some time we agree that they are all at the SAME TEMPERATURE - being - as we say - heated through. We now place
them on a slab of paraffin and an astonishing thing is witnessed.
They sink to different levels - to different depths. That is -
they MELT different amounts of paraffin. That is - they DO
DIFFERENT AMOUNTS OF WORK. They therefore contained
DIFFERENT AMOUNTS OF HEAT ENERGY. But they were all
at the SAME TEMPERATURE. Thus we distinguish HEAT and TEMPERATURE.

C. Again - to distinguish HEAT and TEMPERATURE: We have two
ordinary potatoes - a BIG one and a SMALL one. We have baked
these - so we IMAGINE - IMAGINATION IS A VERY NECESSARY INGREDIENT of our work - and they are therefore at the
SAME TEMPERATURE. But - clearly - there is vastly MORE
HEAT ENERGY in the bigger one.

D. We have two beakers - one with a little water - one with much
water - and a thermometer tells us that they are at the SAME
TEMPERATURE. But they have DIFFERENT HEAT ENERGIES.
E. Again we have two beakers - one with a little water - one with
much water - and a thermometer tells us that the LITTLE water is
at a HIGHER TEMPERATURE. These systems could have the same
amount of HEAT ENERGY.
By the TEMPERATURE of a system we will mean this: The average kinetic energy of the elementary parts - 1/2 mv^2 - the bar over the v meaning average v. By the HEAT - or HEAT ENERGY of a system we will mean this: the SUM of all the kinetic energies of these elementary parts.

F. We have a beaker with ice cubes in it. The thermometer reads
0°C. This is the TEMPERATURE of the system. Now let us add
some thermal energy - some HEAT ENERGY - to the system -
as by heating below with a candle flame - and what do we see
happen? The TEMPERATURE remains unchanged as long as there
is any ice. We are adding HEAT ENERGY but NOT changing the
TEMPERATURE. The heat energy being added serves only to change
the STATE - not the TEMPERATURE. The heat energy of the system is getting more but the temperature is not changed.

G. We have two beakers with water: One is cold water - one is hot
water. We drop into each a bit of red dye. The diffusion takes
place at different rates - faster in the hotter system. The motion
in the hotter system is the faster.

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.

Comments

There are no comments. Be the first to post one.
  Post comment as a guest user.
Click to login or register:
Your name:
Your email:
(will not appear)
Your comment:
(max. 1000 characters)
Are you human? (Sorry)