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 333 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
Excellent


vickyvicksss

  • Member
  • Posts: 351
Reply 3 on: Yesterday
Great answer, keep it coming :)

 

Did you know?

Vital signs (blood pressure, temperature, pulse rate, respiration rate) should be taken before any drug administration. Patients should be informed not to use tobacco or caffeine at least 30 minutes before their appointment.

Did you know?

Approximately one in four people diagnosed with diabetes will develop foot problems. Of these, about one-third will require lower extremity amputation.

Did you know?

Patients who have undergone chemotherapy for the treatment of cancer often complain of a lack of mental focus; memory loss; and a general diminution in abilities such as multitasking, attention span, and general mental agility.

Did you know?

Anti-aging claims should not ever be believed. There is no supplement, medication, or any other substance that has been proven to slow or stop the aging process.

Did you know?

Hypertension is a silent killer because it is deadly and has no significant early symptoms. The danger from hypertension is the extra load on the heart, which can lead to hypertensive heart disease and kidney damage. This occurs without any major symptoms until the high blood pressure becomes extreme. Regular blood pressure checks are an important method of catching hypertension before it can kill you.

For a complete list of videos, visit our video library