« previous next »

Author Question: A ruby laser beam ( = 694.3 nm) is sent outwards from a 2.7-m diameter telescope to the moon, ... (Read 98 times)

big1devin

  • Hero Member
  • *****
  • Posts: 583
on: Jul 28, 2018
A ruby laser beam ( = 694.3 nm) is sent outwards from a 2.7-m diameter telescope to the moon, 384,000 km away. What is the radius of the big red spot on the moon?
 a. 500 m
  b. 250 m
  c. 120 m
  d. 1.0 km
  e. 2.7 km

Question 2

The Moon's average density is
 a. greater than Earth's.
  b. less than Earth's.
  c. approximately the same as Earth's.
  d. nonexistent because water is not present.


makaylafy

  • Sr. Member
  • ****
  • Posts: 347
Reply #1 on: Jul 28, 2018
Answer to Question 1

c

Answer to Question 2

b


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question

big1devin

  • Hero Member
  • *****
  • Posts: 583
Reply #2 on: Jul 28, 2018
Thanks


makaylafy

  • Sr. Member
  • ****
  • Posts: 347
Reply #3 on: Jul 28, 2018
Welcome :)


« previous next »
 

Did you know?

To combat osteoporosis, changes in lifestyle and diet are recommended. At-risk patients should include 1,200 to 1,500 mg of calcium daily either via dietary means or with supplements.

Did you know?

About one in five American adults and teenagers have had a genital herpes infection—and most of them don't know it. People with genital herpes have at least twice the risk of becoming infected with HIV if exposed to it than those people who do not have genital herpes.

Did you know?

For about 100 years, scientists thought that peptic ulcers were caused by stress, spicy food, and alcohol. Later, researchers added stomach acid to the list of causes and began treating ulcers with antacids. Now it is known that peptic ulcers are predominantly caused by Helicobacter pylori, a spiral-shaped bacterium that normally exist in the stomach.

Did you know?

The U.S. Preventive Services Task Force recommends that all women age 65 years of age or older should be screened with bone densitometry.

Did you know?

During the twentieth century, a variant of the metric system was used in Russia and France in which the base unit of mass was the tonne. Instead of kilograms, this system used millitonnes (mt).

Near side of the Moon Near side of the Moon
The Moon The Moon
The same star field photographed with (a) a ground-based telescope, which is subject to poor seeing The same star field photographed with (a) a ground-based telescope, which is subject to poor seeing
Moon orbit Moon orbit
Moon Golf Moon Golf
Earth-Moon-Sun Positions during the Neap Tide Earth-Moon-Sun Positions during the Neap Tide
Video: Tuberculosis Testing

For a complete list of videos, visit our video library