NSCI 111 ASTRONOMY TEST #2 6/15/07 Dr.
Holmes NAME
ANSWER ALL THE QUESTIONS. THE WORTH OF EACH
QUESTION IS IN () AFTER THE QUESTION.
1) Properties of Light
a)
Name one property of light that can be explained by both the wave theory
and the particle theory: (2 points)
b)
Name one property of light that can be explained ONLY by the wave
theory: (2 points)
c)
Name one property of light that can be explained ONLY by the particle
theory: (2 points)
2) Indicate the order of colors according to
energy of the photon. Do this by placing 1 after the color with the smallest
energy photon, 2 after the color with the next to smallest energy photon, etc.
up to 6 after the color with the largest energy photon. (6 points)
____ green
____ blue
____ yellow
____ red
____ orange
____ violet
3) Indicate the order of types of radiation
(light) according to energy of the photon. Do this by placing 1 after the type
with the smallest energy photon, 2 after the type with the next to smallest
energy photon, etc. up to 6 after the type with the largest energy photon. (6
points)
____ ultraviolet
____ infrared
____ x-rays
____ microwave
____ visible
____ radio
4)
Spectra
a) What is an emission spectrum? (4
points)
b) What is a continuous spectrum? (4 points)
5) Magnification of a telescope:"
a)
A telescope has an objective lens of diameter 4 inches and focal
length 100 cm. If an eyepiece of focal length 40 mm (40
mm = 4 cm) is used, what is the
magnifying power of this telescope? (5 points)
b)
If a magnifying power of 200 is desired, what should the focal length of the
eyepiece be for this telescope? (5 points)
c)
What is the maximum useful magnification of this telescope? (5 points)
6) Draw a picture of a reflecting
telescope with a Cassegranian focus and be sure to label all the
relevant elements: (8 points)
7) What are the three major properties of a
telescope, and what does each depend on?
a)
(4 points)
b)
(4 points)
c)
(4 points)
8) Size of the earth
a)
What is the approximate circumference for the earth (be sure to specify
either miles or kilometers)? (5 points)
b)
What is the approximate radius for the earth - that is, the distance
from the surface to the center of the earth (specify miles or kilometers)? (3
points)
c)
How high above sea level is the highest mountain (use the same units as you
used in part b above)? (3 points)
9) What are the main forces that affect the
earth’s surface? (6 points)
10) Effect of the atmosphere on light:
What are the three major ways the atmosphere
affects light from astronomical objects? Give one example of each. (2 points
for each way, 2 points for each example)
a)
example:
b)
example:
c)
example:
11) TRUE or FALSE (+1 for each correct, 0
for each left blank, -1 for each one wrong
(or
based on subtracting from 100: -0 if correct, -1 if blank, -2 if wrong)
__F___ a) A star with a surface
temperature the same as the sun's and moving towards the sun (and earth) will
have its energy peak in the orange (rather than in the green‑yellow like
the sun) when viewed from the earth.
__T___ b) A
red photon has a higher energy and a smaller wavelength than an infrared
photon.
__T___ c) Light passing
through an opening (such as the objective lens of a telescope) spreads out
behind the opening (like a wave rather than a particle). This is one of the main reasons that a
telescope has a maximum useful magnification.
__T___ d) A telescope
whose objective lens has a diameter of 4 inches and a focal length of 100 cm
will collect about four times as much light as a telescope whose objective lens
has a diameter of 2 inches and a focal length of 50 cm.
__F___ e) The earth is significantly
cooler than the moon because it’s volcanoes emit so much heat.
__F___ f) The atmosphere
has about equal amounts of oxygen and carbon dioxide.
__T___ g) We can determine the mass of the earth by observing the
motions of the Moon as it orbits the earth.
__F___ h) The age of
the earth is about 4½ million years
old according to science’s best estimate, and this age is supported by
radioactive dating.
__F___ i) The winds in the Northern Hemisphere rotate
counterclockwise around a low pressure center because the earth is moving
around the sun.
__T___ j) Stars do not twinkle when viewed from the
Moon.