## Watch Lecture 5 https://youtu.be/aeaaz0aHBHg For each of (a), (b), (c), (d), an

Watch Lecture 5

For each of (a), (b), (c), (d), and (e) below, write an answer about 20-40 words long. What were one or more important concepts or equations the speaker on the video was describing:
(a) between 0:01 and 10:00 of the video?
(b) between 10:01 and 20:00 of the video?
(c) between 20:01 and 30:00 of the video?
(d) between 30:01 and 40:00 of the video?
(e) between 40:01 and the end of the video?
3. For all your answers below, please hand write your answers and calculations, and always
explain your reasoning. Draw sketches whenever helpful, and please use your units correctly. If
you are using any online resources (such as unit conversion tools) give their URL and webpage
title in your answers. Write by hand all of this work – on a separate sheet of paper as needed,
especially for the sketches.
[a] Read the OpenStax Astronomy textbook, Section 3.1 (The Laws of Planetary Motion). Write a
total of roughly 50 words that describe each of Kepler’s three laws of orbital motion.
[b] Using Kepler’s third law (also known as the Harmonic Law), calculate the orbital period of an
asteroid around the Sun if the distance between the asteroid and the Sun is Z astronomical units
(AU) and the constant of proportionality K is equal to 1.00 (yr)
2
/(AU)
3
.
Note: The first part of this video https://www.youtube.com/watch?v=EI2bmzuMIAM (titled
“Prof Kevin Kimball-SMCC- Astro 100-Calculating Orbits using Keplers Third Law”) may help.
[c] Is this orbital period a long time or a short time compared to things you might experience in
your daily life? Give evidence for your answer, citing any sources you use