Gas impingement flux, problem in substituting constants

[jjshan]

Homework Statement

gas impingement flux density is given by ∅=P/[itex]\sqrt{}2mkT[/itex]
where m- mass of a molecule

show that
∅=3.513*10²²P/[itex]\sqrt{}MT[/itex]
where pressure in torr and M-molar mass of molecule
then ∅ in molecules per cm² per second

Homework Equations

∅=3.513*10²²P/[itex]\sqrt{}MT[/itex]
where pressure in torr and M-molar mass of molecule
then ∅ in molecules per cm² per second

The Attempt at a Solution

i substitute 1/133 to change pressure scale to torr and multiply by square root of Avogadro no and divide it by square root of 2∏k but i couldn't get appropriate constant. how derive the equation in given scale?

 

[TSny]

Homework Statement
gas impingement flux density is given by ∅=P/[itex]\sqrt{}2mkT[/itex]
where m- mass of a molecule

It looks like you left out a factor of ##\pi## in the square root of the equation.

Consider:

What are the units of ∅ in the SI system?

What are the units of m in SI system?

What are the units of M?