Download Due April 2 - Department of Physics and Astronomy

ASTR 1010-004 — Survey of Astronomy — Spring 2008
Homework Assignment 5, Due Wednesday, April 2, 2008
Choose the best answer for each of the following and explain your reasoning with one or
more complete sentences (required for full credit). Four points each question, 20 points
total. Answers must be turned in on paper; do not email. Please write your
name on each sheet that you hand in.
1. Which of these groups of particles has the greatest mass?
(a) A helium nucleus with two protons and two neutrons
(b) Four individual electrons
(c) Four individual protons
2. Scientists estimate the temperature at the center of the Sun using
(a) probes that measure changes in the Earth’s atmosphere
(b) mathematical models that apply physical laws to the Sun’s interior
(c) miniature versions of the Sun that are constructed in laboratories
3. Why do sunspots appear darker than their surroundings?
(a) They are cooler than their surroundings.
(b) They block some sunlight.
(c) They do not emit any light.
4. If the star Alpha Centauri were moved to a distance 10 times greater than its actual
distance, its parallax angle would
(a) get larger
(b) get smaller
(c) stay the same
5. What properties of a star do we need to measure in order to determine a star’s
luminosity?
(a) apparent brightness and mass
(b) apparent brightness and temperature
(c) apparent brightness and distance
Extra credit on this assignment: for up to 5 questions that you missed on Quiz 5, give
the correct answer, and on a separate sheet (not your test paper!), explain why
that answer is correct. Turn in your test paper and score report with this homework.
(One point per question; credit only with correct explanation.)