Physics 10 Final Exam Physics for future Presidents May 20, 2003

Last name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ First
name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_SID\_\_\_\_\_\_\_\_\_\_\_

**Choose one essay question from list A and one from list B. Put your
name on three pages: the top page for A, for B, and for C (the multiple
choice questions).**

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**Essay question A** (20 pts): \"The trouble with most folks isn\'t
their ignorance, it is knowing so many things that aren\'t true.\" Pick
**one** and only one of the next two questions to answer. Write a page
or two (or whatever is appropriate) on this sheet. Cover the important
points in a clear and concise manner -- as if you have only a few
minutes to tell the President (or your roommate) what he needs to know.
Clear, effective writing is important.

1\. President Bush has announced that the United States will develop a
\"hydrogen economy.\" Describe what this means. What mistaken ideas do
some people have about such an economy? How will hydrogen be used?

**OR**

2\. Radioactivity is widely feared, and misunderstood. Discuss the real
dangers, and the ones that are myths. Describe historical events that
illustrate your points.

**Essay question B** (20 pts): pick **one** and only one of the next two
questions to answer. Write a page or two (or whatever is appropriate) on
this sheet. Cover the important points in a clear and concise manner --
as if you have only a few minutes to tell the President (or your
roommate) what he needs to know. Clear, effective writing is important.

3\. Pick several important/interesting examples of physics principles
used in national defense. Describe how understanding weapons technology
helps us to know what weapons are most likely to be developed by
terrorists and other potential adversaries.

# OR

4\. Why the electricity from the wall is AC rather than DC? Describe
what important physics principles go into making the choice, Describe
how this happened historically, and what you think might happen in the
future.

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Physics 10 Final exam -- Short Questions May 20, 2003

Last name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ First
name\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_SID\_\_\_\_\_\_\_\_\_\_\_

**C. Short questions** (1 point each, 40 points total). Read the
questions carefully so that you don't misinterpret them (e.g. by missing
a word such as "not").

1\. A political poll says that it has an error of plus or minus 3%. That
is based on:

> ( ) The doubling rule
>
> ( ) The square-root rule
>
> ( ) Moore\'s law
>
> ( ) Information theory

2\. The age of the universe is approximately:

> ( ) 14 x10^6^ years
>
> ( ) 14 x10^7^ years
>
> ( ) 14 x10^8^ years
>
> ( ) 14 x10^9^ years

3\. Dark energy makes the Universe

( ) slow down

( ) speed up

( ) expand

( ) maintain constant size

26\. Fuels used in today\'s nuclear reactors include (mark all that are
correct):

> ( ) U-235
>
> ( ) U-238
>
> ( ) Plutonium
>
> ( ) Tritium

5\. The source of energy in the sun is most similar to that in

> ( ) a fission bomb
>
> ( ) a hydrogen bomb
>
> ( ) matter-antimatter annihilation
>
> ( ) a hybrid engine

6\. In the Big Bang theory,

> ( ) the Earth is at the center of the Universe
>
> ( ) the Earth is near the center of the Universe
>
> ( ) the center of the Universe is not known
>
> ( ) there is no center to the Universe

7\. A \"Stop\" sign is bright when you shine the headlamps of your car.
It most likely is covered with:

> ( ) fluorescent paint
>
> ( ) phosphorescent paint
>
> ( ) tritium
>
> ( ) small glass spheres

8\. We measure that a particle travels at the speed of light. (Be
careful; only one answer is correct.) We conclude:

> ( ) its energy is infinite
>
> ( ) it violates Special Relativity
>
> ( ) its energy is zero
>
> ( ) its rest mass is zero

9\. Diamonds are pretty because in them

( ) light travels very slowly

( ) light travels very fast

( ) there is color dependent absorption

( ) light velocity depends on color

10\. The advertising slogan \"Whiter than white\" means that the
material:

> ( ) emits IR
>
> ( ) emits visible light
>
> ( ) absorbs IR
>
> ( ) emits UV

11\. Infrared radiation can (check all that apply):

> ( ) help snakes locate prey
>
> ( ) create ozone
>
> ( ) cause cancer
>
> ( ) cause sunburn

12\. Fiber optics are used instead of radio for communication because:

> ( ) light has more power
>
> ( ) light is cheaper
>
> ( ) light has a higher frequency
>
> ( ) light travels faster

13\. Mark all that are units of power

> ( ) horsepower
>
> ( ) watt
>
> ( ) electron-volt
>
> ( ) joule

14\. Which of the following forms of radiation is *least* likely to
cause cancer?

> ( ) gamma
>
> ( ) microwave
>
> ( ) alpha
>
> ( ) beta

15\. Helium comes from stopped

> ( ) alpha rays
>
> ( ) beta rays
>
> ( ) neutrons
>
> ( ) fission fragments

16\. The freezing point of water is (mark all which are correct)

> ( ) 0 K
>
> ( ) 0 F
>
> ( ) 0 C
>
> ( ) 32 C

17\. If a healthy teenager runs quickly up a flight of stairs, he is
using about

> ( ) 0.001 horsepower
>
> ( ) 0.01 horsepower
>
> ( ) 0.1 horsepower
>
> ( ) 1 horsepower

18\. A \"heat seeking\" missile actually aims itself towards

> ( ) infrared light
>
> ( ) ultraviolet light
>
> ( ) visible light
>
> ( ) radio waves

19.. Ozone depletion is caused by (check all that are correct)

> ( ) CFCs
>
> ( ) carbon dioxide
>
> ( ) fossil fuels
>
> ( ) cosmic rays

20\. A tree keeps dew from forming because:

> ( ) it absorbs starlight
>
> ( ) it keeps air from rising
>
> ( ) if emits infrared radiation
>
> ( ) it blocks the clouds

21\. In a tungsten light bulb, most of the energy goes into

> ( ) visible light
>
> ( ) red light
>
> ( ) ultraviolet light
>
> ( ) infrared light

22\. JDAMS make use of

> ( ) laser guidance
>
> ( ) infrared guidance
>
> ( ) radar guidance
>
> ( ) GPS guidance

23\. Waves tend to bend in the direction that

> ( ) wave velocity is slower
>
> ( ) wave velocity is faster
>
> ( ) is upward
>
> ( ) is downward

24\. Mark ALL that are true:

( ) thunderclouds rise to the ozone layer

> ( ) the sound channel is near the ozone layer
>
> ( ) even without fossil fuels, the atmosphere acts as a greenhouse
>
> ( ) the greatest ozone depletion is over Antarctica

25\. When going downhill, a hybrid automobile

> ( ) turns all the extra energy into heat
>
> ( ) uses 1/4 to 1/2 as much fuel
>
> ( ) uses electric power only
>
> ( ) recharges the batteries

26\. A large electric power plant produces about

> ( ) 1,000 watts
>
> ( ) 1,000,000 watts
>
> ( ) 1,000,000,000 watts
>
> ( ) 1,000,000,000,000 watts

27\. Sound, going through a doorway will spread more if

( ) the doorway is narrow

> ( ) the doorway is wide
>
> ( ) spreading is independent of the width

28\. cancer is most likely to be cause by

> ( ) infrared radiation
>
> ( ) microwave radiation
>
> ( ) ultraviolet radiation
>
> ( ) white light

29\. The radiation from Chernobyl that killed thousands came from

> ( ) neutrons
>
> ( ) cosmic rays
>
> ( ) tritium
>
> ( ) fission fragments

30\. The number of people who died of cancer from the Hiroshima nuclear
bomb is closest to (careful; possibly a trick question)

( ) 500

( ) 5,000

( ) 50,000

( ) 150,000

31\. Identify which are the particles that pass easily through the
Earth:

( ) cathode rays

( ) x-rays

( ) neutrons

( ) neutrinos

32\. A piece of glass feels cool to the touch because

( ) it cools itself by infrared radiation

( ) it conducts heat rapidly from your skin

( ) glass remains cooler than room temperature

( ) it is an illusion because glass is smooth

33\. To make a black hole, we need

( ) high mass in a small radius

( ) high mass in a large radius

( ) low mass in a small radius

( ) extremely dense material in any radius

34\. The P and S waves arrive two seconds apart. The epicenter distance
is:

( ) 2/5 of a mile

( ) 1 mile

( ) 5 miles

( ) 10 miles

35\. In frequency, an octave is a factor of

( ) 2

( ) 4

( ) 8

( ) 16

36\. When a radioactive rock travels near the speed of light

( ) its mass gets greater and there are fewer decays

( ) its mass gets greater and there are more decays

( ) its mass gets less and there are fewer decays

( ) its mass gets less and there are more decays

37\. Ordinary magnetism is created by

( ) moving magnetic monopoles

( ) stationary charges

( ) electric current

( ) stationary magnetic monopoles

38\. Electricity will heat a wire if it has

( ) high voltage

( ) high current

( ) high frequency

( ) DC rather than AC

39\. One horsepower is approximately equal to

( ) 1 watt

( ) 20 watts

( ) 1 kilowatt

( ) 1 megawatt

40\. The wavelength of visible light is closest to:

> ( ) 1 mm
>
> ( ) 1 micron
>
> ( ) 10^-8^ cm
>
> ( ) 10^-13^ cm