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

Author Question: How does a rocket launch upwards? Choose the statement that best describes why a rocket goes up. ... (Read 82 times)

JGIBBSON

  • Hero Member
  • *****
  • Posts: 538
on: Jul 27, 2018
How does a rocket launch upwards? Choose the statement that best describes why a rocket goes up.
 
  A) By expelling gas downwards, the rocket is propelled upwards.
  B) By expelling gas, the rocket loses mass; because it is lighter, it rises up.
  C) By expelling gas downwards, which pushes against the ground, the rocket is propelled upwards.

Question 2

In order for the cosmic microwave background to show hydrogen absorption lines at the redshift corresponding to the universe's age of 380,000 years, what condition would have been necessary?
 
  A) There would have needed to be even warmer hydrogen clouds (which would contradict the observation of a uniform temperature in all directions).
  B) There would have needed to be cooler hydrogen clouds (which would contradict the observation of a uniform temperature in all directions).
  C) There would have needed to be ionized hydrogen (which would contradict the idea that the CMB originates at the time the universe cooled enough for protons and electrons to combine, making neutral atoms).


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

pikon

  • Sr. Member
  • ****
  • Posts: 361
Reply #1 on: Jul 27, 2018
Answer to Question 1

A

Answer to Question 2

B


JGIBBSON

  • Member
  • Posts: 538
Reply 2 on: Jul 27, 2018
Thanks for the timely response, appreciate it

deja

  • Member
  • Posts: 332
Reply 3 on: Yesterday
Wow, this really help

« previous next »
 

Did you know?

Giardia is one of the most common intestinal parasites worldwide, and infects up to 20% of the world population, mostly in poorer countries with inadequate sanitation. Infections are most common in children, though chronic Giardia is more common in adults.

Did you know?

More than one-third of adult Americans are obese. Diseases that kill the largest number of people annually, such as heart disease, cancer, diabetes, stroke, and hypertension, can be attributed to diet.

Did you know?

Although not all of the following muscle groups are commonly used, intramuscular injections may be given into the abdominals, biceps, calves, deltoids, gluteals, laterals, pectorals, quadriceps, trapezoids, and triceps.

Did you know?

Women are 50% to 75% more likely than men to experience an adverse drug reaction.

Did you know?

Less than one of every three adults with high LDL cholesterol has the condition under control. Only 48.1% with the condition are being treated for it.

The correct statement about hormones-insulin and glucagon The correct statement about hormones-insulin and glucagon
Choose the telephone unit that offers the features needed in your office. Choose the telephone unit that offers the features needed in your office.
Example of a patient statement. Example of a patient statement.
A typical bank statement. A typical bank statement.
How to choose the right payment plan with changing conditions (Question 5) How to choose the right payment plan with changing conditions (Question 5)
A bank statement shows a balance of $2,970.31 The check register of the account owner shows an ... A bank statement shows a balance of $2,970.31 The check register of the account owner shows an ...
Video: Alternative Energy Sources

For a complete list of videos, visit our video library