How Does a Small Sample of Gas Exert Great Force on a Cube's Faces?

  • Thread starter Thread starter Dr.Wasim
  • Start date Start date
Click For Summary
SUMMARY

The discussion focuses on calculating the force exerted by a small sample of gas contained in a cube measuring 10.0 cm on each edge, filled with air at atmospheric pressure (1 atm) and a temperature of 300K. Using the Ideal Gas Law (PV=nRT) and the conversion of pressure from atmospheres to Pascals (1 atm = 1.013 x 10^5 N/m²), participants confirmed that the force exerted on each face of the cube is 1013 Newtons. The underlying physical reason for this significant force from a small gas sample is attributed to the high number of gas molecules colliding with the cube's walls at high velocities, resulting in substantial pressure.

PREREQUISITES
  • Understanding of the Ideal Gas Law (PV=nRT)
  • Knowledge of pressure conversion from atmospheres to Pascals
  • Basic principles of force calculation (Force = Pressure x Area)
  • Familiarity with gas molecular behavior at different temperatures
NEXT STEPS
  • Research the Ideal Gas Law applications in real-world scenarios
  • Learn about molecular kinetic theory and its relation to gas pressure
  • Explore the concept of pressure in different states of matter
  • Investigate the effects of temperature on gas behavior and molecular velocity
USEFUL FOR

This discussion is beneficial for physics students, educators, and anyone interested in understanding gas behavior, pressure calculations, and the principles of thermodynamics.

Dr.Wasim
Messages
12
Reaction score
0

Homework Statement



A cube 10.0 cm on each edge contains air ( with equivalent molar mass 28.9 gm/mol ) at
atmospheric pressure and temperature 300K. Find (a) the mass of the gas, (b) its weight,
(c) the force it exerts on each face of the cube. (d) Comment on the underlying physical reason why such a small sample can exert such a great force.


( I know it is simple quastion but i want to sure from my answer )

please i need the answer today

best wishes for you
 
Physics news on Phys.org
You will need the ideal gas law:
PV=nRT

Then write down what you know and your unknowns and see where you can go from that?
R is a constant R = 8.314472 J/(K*mol)

your pressure is a known btw, it says it is at atmospheric pressure.
 
ok

i found mass from ideal law

then

weight = mg

ok ?

now force = P * A right ?

p = 1 atm = 1.013 * 10^5 N/m^2 . are u sure ?

then i found F

ok

i need comment please
 
Dr.Wasim said:
p = 1 atm = 1.013 * 10^5 N/m^2 . are u sure ?

I don't understand where your getting this from.
You had the equation right
Force = Pressure * Area.
So just multiply the atmospheric pressure by the area of one face on the cube. which is 100cm^2.
 
p = 1 atm = 1.013 * 10^5 N/m^2 ( Paskal )

it is known for evret one

and we found force in ( Newten ) so we must convert atm to paskal

now i want the answer for

(d) Comment on the underlying physical reason why such a small sample can exert such a great force.
 
re d) what is gas made up of? what is the average velocity of a gas molecule at 300K? How many are banging into the walls at anyone instant? Thats the sort of thing I think is being sought in the answer.
 
i don' what you mean

now see

i found force and it is equal 1013 newten and it is a great force

we have small sample of gas that exert this force on each face of cube

the quastion now ... what is phyiscal reason for that ?
 

Similar threads

  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 3 ·
Replies
3
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
6K
  • · Replies 7 ·
Replies
7
Views
8K
  • · Replies 2 ·
Replies
2
Views
4K
Replies
5
Views
2K
Replies
2
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
3
Views
2K