Practice Exam 2 Fall - AST101 Section M001 Our Corner of...

AST101 Section M001: Our Corner of the Universe
Exam 2: October 14, 2010
Test Form A
Answer all of the following questions on the bubble sheet provided using a #2 pencil. Make
sure that your Name, Student ID Number and test form letter are on the answer sheet and that
all answers are recorded in the correct position. ALWAYS SELECT THE BEST ANSWER. Each
question is worth 1 point. This is a closed-book, closed-note exam and you have the duration
of class to complete it. If you have questions, please raise your hand. You are not to talk to or
attempt to obtain answers from other students for any reason.
Be sure to bubble in your ID number and test form letter.
DO NOT START THE EXAM UNTIL YOU ARE TOLD TO DO SO!
1

Exam 2 Form A AST101.M001 Fall 2010 2
Choose the best answer from those provided. All questions are worth 1 point.
1. All of the following are steps in the scientific method except:
(a) making observations.
(b) proposing a model.
(c) performing an experiment.
(d) revising a model.
(e) proving a model.
2. How many of the orbits shown below are physically realistic?
Exam continues on next page

Exam 2 Form A AST101.M001 Fall 2010 3
Use the drawing below to answer the next two questions. The planets in the orbits shown
obey Kepler’s laws.
A B C
3. Which of the planets orbits is most like the Earth’s orbit around the Sun?
4. Which of the planets shown would experience the greatest change in speed over the course
of an orbit?
5. Kepler’s third law states that the relationship between the orbital period and semi-major
axis of a planet’s orbit is P
2
= a
3
. To use this equation for planets orbiting the Sun, P must
be expressed in and a must be expressed in .
The table below shows the orbital distances, orbital periods, and masses for the six planets closest
to the Sun. Jupiter is the most massive of these planets at 318 times the mass of the Earth and
Mercury is the least massive of these planets at 0.06 times the mass of the Earth.
Planet
Semi-major axis
in A.U.
Orbital Period
in years
Mass of Planet in
units of the Earth’s mass
Mercury 0.38 0.24 0.06
Venus 0.72 0.61 0.81
Earth 1.0 1.0 1.0
Mars 1.52 1.88 0.11
Jupiter 5.20 11.86 318
Saturn 9.54 29.46 95.2