Physics help?
posted by Megan .
Nitrogen gas molecules, which have mass 4.65×10−26 kg, are striking a vertical container wall at a horizontal velocity of positive 440 m/s. 5.00×1021 molecules strike the wall each second. Assume the collisions are perfectly elastic, so each particle rebounds off the wall in the opposite direction but at the same speed. (a) What is the change in momentum of each particle? (b) What is the average force of the particles on the wall?
If you could also explain this as you go that would be fantastic! Thank you :)

Δp= m•Δv =m•[v –(v)] = 2mv =2• 4.65•10^26•440 =4.1•10^23 kg•m/s.
F•Δt = Δp,
Fₒ = Δp/ Δt =4.1•10^23/1 =4.1•10^23 N.
F=N• Fₒ = 5•10^21•4.1•10^23=0.2 N