Pressure~Gas Law Homework - Find Avg Pressure

  • Thread starter Thread starter clovergogo
  • Start date Start date
  • Tags Tags
    Law
Click For Summary

Homework Help Overview

The problem involves calculating the average pressure exerted by raindrops falling on a circular region. The context includes parameters such as the rate of rainfall, the velocity of raindrops, and the nature of their collisions with the surface.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • Participants discuss the relationship between momentum and pressure, with one suggesting a formula involving mass and velocity. Others question the implications of perfectly elastic collisions on momentum change and how that relates to force and pressure calculations.

Discussion Status

The discussion is active, with participants exploring different approaches to relate momentum and pressure. Some guidance has been offered regarding the use of units and the implications of elastic collisions, but no consensus has been reached on the method to solve the problem.

Contextual Notes

Participants are working under the assumption that the collisions are perfectly elastic and are considering the implications of this on the calculations. There is also a focus on ensuring proper use of units in the calculations.

clovergogo
Messages
4
Reaction score
0

Homework Statement


rain is falling normally on a circular region of radius 25cm at a rate of 1.2gs-1
suppose the velocity of each raindrop just before it reaches the region is 10cms-1
and the collision between each raindrop and the region is perfectly elastic
find the avg pressure exerted on the region

take g=9.8ms-1


Homework Equations



P= F/A

The Attempt at a Solution



momentum, then the Pressure
is it ...P = (0.0012X10+0.0012X9.8) / 0.25^2 pi??
 
Physics news on Phys.org
clovergogo said:

Homework Statement


rain is falling normally on a circular region of radius 25cm at a rate of 1.2gs-1
suppose the velocity of each raindrop just before it reaches the region is 10cms-1
and the collision between each raindrop and the region is perfectly elastic
find the avg pressure exerted on the region

take g=9.8ms-1

Homework Equations



P= F/A

The Attempt at a Solution



momentum, then the Pressure
is it ...P = (0.0012X10+0.0012X9.8) / 0.25^2 pi??
If the collisions are perfectly elastic, what is the change in momentum of a raindrop of mass m striking this area?

Now take N such raindrops every second such that Nm = 1.2 g. What is the total change in momentum of the raindrops every second? How is that change in momentum every second related to the force imparted to the circular area? What is that force/unit area?

AM
 
can i take t=1
then mv-mu/t = F can be count
then mass = 1.2 X 1
then Pressure (P) can be count
 
clovergogo said:
can i take t=1
then mv-mu/t = F can be count
then mass = 1.2 X 1
then Pressure (P) can be count

If you use the units and parentheses properly, the method will work. What is u if the collision is perfectly elastic?

ehild
 

Similar threads

Replies
8
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
Replies
16
Views
4K
  • · Replies 3 ·
Replies
3
Views
3K
  • · Replies 5 ·
Replies
5
Views
4K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
3
Views
2K
Replies
1
Views
6K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K