Explorations: An Introduction to Astronomy

Thomas T. Arny, Stephen E. Schneider

Chapter 7 The Moon - all with Video Answers

Educators

Chapter Questions

Problem 1

Use data from the appendix to calculate the ratio of the Moon's mass to the Earth's, and the ratio the Moon's radius to the Earth's radius.

Donald Albin

Numerade Educator

00:51

Problem 2

Mare Serenitatis has an angular diameter of 5 minutes of arc. What is its diameter in kilometers? (See section $2.1 .$

Ankit Gupta

Numerade Educator

04:03

Problem 3

The crater Tycho is 88 kilometers wide. What is its angular diameter from Earth? Could you see a crater this size with the naked eye?

Daniel Alva

Numerade Educator

01:29

Calculate the Moon's density (see the end of section
6.1 for how to calculate density). The Moon's mass and radius can be found in the appendix. On the basis of your value for the density, what can you say about the amount of iron in the Moon? (See table 6.1 for iron's density.)

Elan Stopnitzky

Numerade Educator

02:09

Problem 5

The density of Swiss cheese is about $1.1 \mathrm{g} / \mathrm{cm}^{3} .$ If the Moon were in fact made of (incompressible) cheese, what would be its mass?

Sarah Mccrumb

Numerade Educator

02:04

Problem 6

The Lunar Reconnaissance Orbiter orbits the Moon 50 kilometers above its surface. Its period is about 113 minutes. Use these values to find the Moon's mass.

Banhishikha Sinha

Numerade Educator

01:09

Problem 7

A laser pulse takes 2.56 seconds to travel from Earth to the Moon and return. Use this to calculate how far away the Moon is. How might this time delay affect conversations between an astronaut on the Moon and someone back on Earth?

Narayan Hari

Numerade Educator

00:52

Problem 8

Because the Earth and Moon are both rocky spheres, we can make a crude estimate of how much faster the Moon cooled than the Earth. Compute the ratio of the surface area to the volume of the Moon, and compare it to the same ratio for the Earth (formulas for surface area and volume, and values of the radii, can be found in the appendix; also review fig. 6.8 .