(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

hi,so iv been trying to work out this problem but im stuck because i dont understand what the lux in the question is,could any one explain it to me?

the question says:

a beam of helium atoms is incident at an angle of 60 degrees on a flat surface of area 0.2 m^2. each atom has a velocity of 3* 10^7 m s^-1 and the beam flux is 10^16 atoms m^-2 s^-1.assuming the beam covers the whole surface what is the force on the surface?

2. Relevant equations

im guessing beam flux is perhaps the intensity,or the amount of atoms which wud pass through 1m^2 of surface in one second?and how exactly could i relate this to the question?should i multiply it by 0.2m^2 to figure out how many wud pass through the surface area in the question in one second?

any hints or direction would be greatly appreciated

3. The attempt at a solution

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# Force question-what is flux?

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