This topic contains a solution. Click here to go to the answer

Author Question: A beam of electrons moves at velocity . The number of particles per unit volume in the beam of area ... (Read 295 times)

saliriagwu

  • Hero Member
  • *****
  • Posts: 537
A beam of electrons moves at velocity . The number of particles per unit volume in the beam of area A is . If we imagine a cylindrical Gaussian surface of radius r and length centered on the beam, the electron flux through the surface is
   
  a.
  0.
   
  b.
  vf A.
   
  c.
  2vf A.
   
  d.
  vf (A+2r).
   
  e.
  2vf (A+r).

Question 2

Gino says that the analog of Gauss's law for the flow of an incompressible fluid of density at constant velocity is for an imaginary surface within the fluid. Lorenzo says that it is true only if the area where the fluid enters the surface and the area where it leaves the surface are both perpendicular to the velocity of the fluid. Which one, if either, is correct?
   
  a.
  Gino, because as much fluid leaves as enters.
   
  b.
  Lorenzo, because is not equal to zero if the fluid enters or exits at angles other than 90.
   
  c.
  Lorenzo, because this is true only when the fluid executes rotational motion.
   
  d.
  Gino, because it is true only when the fluid is enclosed on all sides, not when it is flowing.
   
  e.
  Lorenzo, because it is true only when the fluid is enclosed on all sides, not when it is flowing.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

verrinzo

  • Sr. Member
  • ****
  • Posts: 346
Answer to Question 1

a

Answer to Question 2

a




saliriagwu

  • Member
  • Posts: 537
Reply 2 on: Jul 28, 2018
:D TYSM


brbarasa

  • Member
  • Posts: 308
Reply 3 on: Yesterday
YES! Correct, THANKS for helping me on my review

 

Did you know?

Fungal nail infections account for up to 30% of all skin infections. They affect 5% of the general population—mostly people over the age of 70.

Did you know?

The lipid bilayer is made of phospholipids. They are arranged in a double layer because one of their ends is attracted to water while the other is repelled by water.

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?

Fewer than 10% of babies are born on their exact due dates, 50% are born within 1 week of the due date, and 90% are born within 2 weeks of the date.

Did you know?

The top 10 most important tips that will help you grow old gracefully include (1) quit smoking, (2) keep your weight down, (3) take supplements, (4) skip a meal each day or fast 1 day per week, (5) get a pet, (6) get medical help for chronic pain, (7) walk regularly, (8) reduce arguments, (9) put live plants in your living space, and (10) do some weight training.

For a complete list of videos, visit our video library