When doing calculations, should pressure be in atm or Pa?

AI Thread Summary
When performing calculations involving pressure, it is recommended to use Pascals (Pa) for consistency, especially when calculating work in joules. The ideal gas law requires adjusting constants, such as the gas constant R, to match the chosen units. Using consistent units, such as pressure in Pa and volume in cubic meters, simplifies calculations. It is emphasized to minimize conversions to avoid errors. Overall, maintaining uniformity in units ensures accurate results in calculations.
Lee
Messages
55
Reaction score
0
When doing calculations, should pressure be in atm or Pa? (looking for answers in joules)
 
Physics news on Phys.org
Doesn't matter AFAIK as long as you adjust the constants for example R in PV=nRT.
 
Good'o. I just wanted to double check.
 
Use Pascals. P = F / A, Force is usually given in Newtons amd 1 Pa = 1 Nm^-2.

edit: should read the thread title, good practice anyway :).
 
Last edited:
all you need is to have is consistant units.
pressure in Pa, volume in cubic meters and R = 8.3145 J mol^-1 K^-1
then work will be in joules
 
Last edited:
Always choose the path with the least number of conversions.

Daniel.
 

Thread 'Rolling without slipping on a curved surface'

Kindly see the attached pdf. My attempt to solve it, is in it. I'm wondering if my solution is right. My idea is this: At any point of time, the ball may be assumed to be at an incline which is at an angle of θ(kindly see both the pics in the pdf file). The value of θ will continuously change and so will the value of friction. I'm not able to figure out, why my solution is wrong, if it is wrong .
View full post »

Thread 'Struggling to understand the concept of this question (ice cube in water optics question)'

TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
View full post »

Similar threads

How to calculate pressure when two forces are exerted
Replies
23
Views
1K
Pressure of water coming out of a hose nozzle
Replies
7
Views
992
Convert J/mol k into atm cm^3/mol k
Replies
6
Views
7K
Calculating ΔE Difference for 2 Samples of Monatomic Ideal Gas
Replies
4
Views
2K
Why Water Won't Flow From Faucet with 2000 Pa Pressure?
Replies
15
Views
2K
Pressure higher up in the atmosphere
Replies
13
Views
2K
Pressure inside a sealed container
Replies
9
Views
2K
Calculating work done by a gas
Replies
2
Views
765
Solving Fluid Statics Problem: Accounting for Atmospheric Pressure
Replies
9
Views
2K
What is the relationship between tire size and pressure changes?
Replies
13
Views
990

Hot Threads

Recent Insights

Back
Top