Phy113
posted by ugonnia .
At what temperature will the rootmeansquare speed of oxygen molecules have the value of 640 m/s? 1 kilom has a mass of 32kg.

You will find the formula you need at
http://chemistry.about.com/od/workedchemistryproblems/a/CalculateRootMeanSquareVelocityOfGasParticles.htm
It is:
Vrms = sqrt(3RT/M)
M = 32*10^3 kg/mol
R = ideal gas constant = 8.3145 (kg·m^2/sec^2)/K·mol
You were given the rms speed. Solve for T