« previous next »

Author Question: Segmented mirrors sag under their own weight. Their optical shape must be controlled by ... (Read 24 times)

kellyjaisingh

  • Hero Member
  • *****
  • Posts: 540
on: Jul 27, 2018
Segmented mirrors sag under their own weight. Their optical shape must be controlled by computer-driven thrusters under the mirrors in what is called
 
  a. an achromatic lens.
  b. active optics.
  c. a Schmidt-Cassegrain design.
  d. a Newtonian design.
  e. interferometry.

Question 2

If the stars at the turnoff point of a cluster have a mass of 3 M, what is the age of the cluster?
 
  a. 3.0 x 1010 years
  b. 3.3 x 109 years
  c. 6.4 x 108 years
  d. 1.6 x 1011 years
  e. The age of a star cluster can not be determined from the mass of stars at the turnoff point.


momtoalll

  • Sr. Member
  • ****
  • Posts: 326
Reply #1 on: Jul 27, 2018
Answer to Question 1

B

Answer to Question 2

C


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
« previous next »
 

Did you know?

All adverse reactions are commonly charted in red ink in the patient's record and usually are noted on the front of the chart. Failure to follow correct documentation procedures may result in malpractice lawsuits.

Did you know?

Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.

Did you know?

Many people have small pouches in their colons that bulge outward through weak spots. Each pouch is called a diverticulum. About 10% of Americans older than age 40 years have diverticulosis, which, when the pouches become infected or inflamed, is called diverticulitis. The main cause of diverticular disease is a low-fiber diet.

Did you know?

Approximately one in three babies in the United States is now delivered by cesarean section. The number of cesarean sections in the United States has risen 46% since 1996.

Did you know?

In Eastern Europe and Russia, interferon is administered intranasally in varied doses for the common cold and influenza. It is claimed that this treatment can lower the risk of infection by as much as 60–70%.

The birth weight of human infants is tightly constrained by natural selection. The birth weight of human infants is tightly constrained by natural selection.
Donald Trump Optical Illusion Donald Trump Optical Illusion
This pediatric growth chart tracks the height and weight for girls ages 2–20. This pediatric growth chart tracks the height and weight for girls ages 2–20.
A container in the shape of a right circular cylinder with no top has surface area square feet. A container in the shape of a right circular cylinder with no top has surface area square feet.
Nutrition and Body Weight Nutrition and Body Weight
Sheep Fiber Length (cm) vs Fleece Weight (kg) Sheep Fiber Length (cm) vs Fleece Weight (kg)
Video: Lower Limb Arteries Animation

For a complete list of videos, visit our video library