This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Why are most large telescopes reflectors, not refractors? A) Large lenses deform under their own ... (Read 78 times)

future617RT

  • Hero Member
  • *****
  • Posts: 543
on: Jul 27, 2018
Why are most large telescopes reflectors, not refractors?
 
  A) Large lenses deform under their own weight, but mirrors can be supported.
  B) Large mirrors need only one optical surface, achromats four surfaces to grind.
  C) Reflectors do not suffer from chromatic aberration like refractors do.
  D) Large, very clear lenses are harder to cast than more tolerant mirror blanks.
  E) All of the above are correct.

Question 2

How can we determine the reflectivity of an asteroid?
 
  A) by taking a photograph of it
  B) by measuring its mass and radius
  C) by comparing its brightness in visible light to its brightness in infrared light
  D) by where it is located in the asteroid belt


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

sarahccccc

  • Sr. Member
  • ****
  • Posts: 318
Reply #1 on: Jul 27, 2018
Answer to Question 1

E

Answer to Question 2

C


future617RT

  • Member
  • Posts: 543
Reply 2 on: Jul 27, 2018
Wow, this really help

cassie_ragen

  • Member
  • Posts: 347
Reply 3 on: Yesterday
Thanks for the timely response, appreciate it

« previous next »
 

Did you know?

Signs of depression include feeling sad most of the time for 2 weeks or longer; loss of interest in things normally enjoyed; lack of energy; sleep and appetite disturbances; weight changes; feelings of hopelessness, helplessness, or worthlessness; an inability to make decisions; and thoughts of death and suicide.

Did you know?

According to research, pregnant women tend to eat more if carrying a baby boy. Male fetuses may secrete a chemical that stimulates their mothers to step up her energy intake.

Did you know?

The first monoclonal antibodies were made exclusively from mouse cells. Some are now fully human, which means they are likely to be safer and may be more effective than older monoclonal antibodies.

Did you know?

Interferon was scarce and expensive until 1980, when the interferon gene was inserted into bacteria using recombinant DNA technology, allowing for mass cultivation and purification from bacterial cultures.

Did you know?

For high blood pressure (hypertension), a new class of drug, called a vasopeptidase blocker (inhibitor), has been developed. It decreases blood pressure by simultaneously dilating the peripheral arteries and increasing the body's loss of salt.

The American Lion was one of the abundant Pleistocene megafauna, a wide variety of very large mammal The American Lion was one of the abundant Pleistocene megafauna, a wide variety of very large mammal
Small and large intestines Small and large intestines
Large intestine Large intestine
Grazing Incidence X-ray Telescopes Grazing Incidence X-ray Telescopes
Carbon is constantly exchanged between large reservoirs in the lithosphere Carbon is constantly exchanged between large reservoirs in the lithosphere
As shown in the figure, a large open tank contains a layer of oil ( density 450 kg/m3) floating ... As shown in the figure, a large open tank contains a layer of oil ( density 450 kg/m3) floating ...
Video: Uterine (menstrual) cycle - phases

For a complete list of videos, visit our video library