This preview shows pages 1–2. Sign up to view the full content.
PHYS 445 Lecture 19  MB continued
19  1
© 2001 by David Boal, Simon Fraser University.
All rights reserved; further resale or copying is strictly prohibited.
Lecture 19  MB continued
What's Important:
•
pressure of an ideal gas
Text
: Reif
Pressure of an ideal gas
Our picture of an ideal gas hitting a wall is
With each collision, an amount of momentum 2
mv
z
is transferred to the wall, giving rise
to a pressure, or force per unit area.
If the collisions occur over a time interval
∆
t
, then
for a given value of
v
z
[
momentum change
] = 2
mv
z
• [
collisions per unit time
] •
∆
t
But the force from the collisions is equal to
∆
p
/
∆
t
, so for a given value of
v
z
[
force per unit area
] = 2
mv
z
• [
collisions per unit time per unit area
] •
∆
t
/
∆
t
.
That is, the pressure from
v
z
is
[
pressure
] = 2
mv
z
• [
collisions per unit time per unit area
].
Now, the [
collisions per unit time per unit area
] is also called the flux.
If the particles all
moved perpendicular to the wall, then the flux would be
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 09/07/2009 for the course PHYS 445 taught by Professor Davidboal during the Spring '08 term at Simon Fraser.
 Spring '08
 DavidBoal
 Physics, Momentum

Click to edit the document details