Science Workshop #2
Energy & The Laws of Thermodynamics
"[Thermodynamic theory]…
is the only physical theory of universal content which, I am convinced,
that within the framework
of applicability of it basic concepts, will never be overthrown."
- Albert Einstein
Questions:
1) Rub your hands together
as fast as you can for 15 seconds. Describe the physical sensation that
results, particular with respect to any change in temperature you experience.
Where did the energy come from to cause this change? What was its ultimate
source? Draw a diagram that illustrates the transformations this energy
went through from its "beginning" to your hands.
2) After your hands come
back to normal, consider where the energy went? What is its ultimate fate?
3) On the Columbia River
there are many hydroelectric power plants. Describe the transformations
of energy that occur when hydroelectricity is produced. Begin your analysis
with seawater in the ocean. How does it get into the river? What does it
do next? Imagine the electricity is used to power a computer. What ultimately
happens to the energy of the river?
4) Consider the following
scheme. An inventor plans to use some of the hydroelectricity generated
by a dam to pump water back uphill so it can be repeatedly to generate
more power. Is this a feasible idea? Explain why or why not.
5) Can you cool your house
by leaving the refrigerator door open? Why or why not?
6) Explain the various types
of energy transformations that occur in a waterfall. Do you expect there
to be a difference in the water temperature at the top and bottom of the
waterfall?
7) In light of the First
Law, explain how it is possible to have an energy "crisis". Explain.
8) Entropy has sometimes
been called "time's arrow". Explain what is meant by this term in light
of the directionality of spontaneous changes.