Download sample exam 1

Astronomy 115
Sample astronomy exam 1 (first three weeks plus)
Open textbook (no other textbooks), open notes, homework, handouts, calculator; no
collaboration. This part of the exam is worth 60 points and is timed for fifty minutes.
Short answer
1. Draw the heliocentric model of the solar system, including only the Sun and Earth,
from a viewpoint at the celestial north pole. Use the standard astronomical
symbols for those bodies. Indicate with an arrow the direction in which the Earth
orbits.
2. On the same drawing above, indicate with an arrow the direction in which the Earth
rotates, and place a stick figure person on the Earth where that person would be
experiencing midnight.
3. A planet is moving most quickly in its orbit at:
a. aphelion
b. perihelion
c. semi-major axis distance
d. never
(always same speed)
4. A planet is closest to the Sun at:
a. aphelion
b. perihelion
c. semi-major axis distance
d. never
(always same distance)
5. At noon, the Sun is currently in the constellation Virgo. One month ago (at noon),
the Sun was in:
a. in Libra (the next constellation)
b. in Virgo
c. in Leo (the previous constellation)
d. none of these
6. Equation variable explaining: Explain, for each of the equations below, what the
variable in question stands for.
P2 = a3
F =
€
G m1 m2
r2
P is the _______________________ of an object
F is the force of ________________________
7. Match a small letter (principle of physics) with a large letter (example of that
principle):
a. Kepler’s first law
A. The planets all orbit the Sun in
the same direction.
b. Newton’s first law
B. The orbit of a planet is elliptical, with
one of the foci of the orbit at the Sun.
c. The conservation of angular momentum
C. The reason that an object can
orbit a more massive object.
8. True or false:
a. There is a star that rises over the western horizon.
b. It is possible to tell the date by the shadow of a sundial.
Essay questions— choose two of the three questions; circle the numbers of the ones
chosen, so I know which ones to grade. Please answer each question in
sentence/paragraph format or a drawing, depending on what is asked.
9. In the 1996 movie Independence Day, an alien ship with “a quarter [of] the mass of
the Moon” comes from outside the solar system and enters orbit around Earth. Nothing
on Earth seems affected by that spacecraft. Apart from the whole alien thing, is this “no
effect” scenario reasonable? Use qualitative arguments using the Moon’s effect on Earth
in comparison to the spaceship’s effect on Earth. The alien ship’s orbit is roughly onetenth of the distance to the Moon from Earth.
10. You are sitting on a spaceship orbiting the Earth. Your back is to the Earth, and the
spaceship is moving to the right (from where you sit). You gently toss a ball directly
away from you. Does the ball (a) hit the wall to the left, (b) hit the wall to the right, (c)
hit the wall in front of you, (d) hit the floor or (e) come back to you? Whichever answer
you choose, cite a physics principle and how that principle applies to this situation.
11. You, the famous astronaut, land on a newly-discovered planet. You note that there is
a star right on the northern horizon around which all the other stars in the sky revolve.
You call that star “Nicky Minaj”. You get in your planet buggy and drive 1000 km north
(you have a lot of patience), but the buggy runs out of fuel. You note that Nicky Minaj
now has an altitude of 45°. What is the circumference of the planet? Show exactly
(either equations or a drawing) how you got your answer.
Combined astronomy/math question
12. Consider the following information about two stars:
Luminosity (Lsun)
Distance (pc)
Star V
Star W
0.5
0.5
30
10
Lsum is solar luminosities. Which star is brighter, and by what factor over the other
star? Show details of your calculation. Why was the information about the luminosities
important?
Or there may be a graphing-some-data question, similar to the graph on Lab 2 (we
haven’t decided).