Background
Humankind has always tried to understand and control heat. Our understanding,
which first kept us from freezing in Winter, grew until we learned how to
convert heat into the mechanical energy which drives industry. Now we understand
even the thermonuclear processes which light our sun and all other stars.
This Heat and Temperature unit explores several key ideas concerning the
measurement and control of heat. Feedback is a theme which threads through
the history of our study of heat. Feedback is at work in thermostats, homiostatis,
and heat engines.
Goals
This unit presents several projects which will help you understand heat.
You start by learning how to measure temperature and then go on to how to
control it. As the unit unfolds, you are introduced to the major concepts
of heat and temperature that are usually taught in physics, but through
a series of interesting projects. In the -Messing Around-
section you will get a feeling for ways in which temperature can be measured. After learning about
temperature measurement, work through the -Core Project-
and then choose an - Extension-
and use what you have learned to investigate more about Heat & Temperature
By the end of this unit, you should be able to:
Explain the difference between heat and temperature and give examples
of cases where added heat does not result in increased temparature.
Use several different sensors to measure temperature, be able to calibrate
them, explain their underlying physics, and estimate their accuracy.
Be familiar with the various units commonly used for temperature,
thermal energy, heat flow, heat capacity, and thermal insulation.
Be able to design, construct, describe, evaluate, and model a thermal
regulation system.
Describe the factors that influence heat flow and quantitatively relate
heat flows to values of these factors.
Give operational definitions of absolute zero, temperature scales,
feedback, oscillilation, heat capacity, and thermal insulation.
Be able to estimate temperatures and heat flows commonly found in
nature.
Construct a concept map that shows the relation between the most important
ideas in thermal physics.
Trace the flow of energy in systems that involve thermal energy and
its conversion to or from other forms of energy.
The Learning Strategies:
Learn by Doing
Most people learn concepts by making things and then thinking about them.
Too often students try to jump ahead and memorize the equations and definitions
without giving themselves time to think. This is why Hands-On-Physics units
emphasize "hands on" building.
HOP Structure There are three major sections to each unit: "messing around,"
a "core project," and then "extensions." The "messing
around" part is a chance to learn the big physics concepts without
worrying about a lot of details and computations. The "core project"
is an extended construction project that everyone does. Then you choose
one of a number of "extensions" to work on.
Think in Lab It is important that you use your mind while you are in the lab doing
these various projects. You cannot just follow the directions and fill in
the blanks. We don't tell you every little step because you should be learning
how to do things yourself. Eventually, we want you to be able to undertake
an entire project. To get to this level, you have to make larger and larger
steps without help.
Fill in the Gaps You may find this frustrating. You may get mad at the instructions that
seem vague and you may wish your teacher could help you all the time. But
before asking for help, talk it out in your group; try to invent a way out
of your problem. If you are not sure whether you are doing the "right
thing", write down what your problem was and what you decided.
Make Mistakes Rapidly Remember, it is okay to make mistakes; we learn from our mistakes. Always
think about safety and try to avoid breaking things. But if you make a mistake,
don't be discouraged; just try again. The more mistakes you make, the more
you must be learning.
