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Grade 12Thermal Physics

At the time when we find Vrms of H2 and O2 gas it came different but there will be same average kinitic energy ?? Why (assume T is same). I mean why mass is not coming in kE wanna know ?

Profile image of vadu
10 Years agoGrade 12
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1 Answer

Profile image of Ashutosh Mohan Sharma
10 Years ago
Kinetic energy=1/2* MV(rms)^2….....1
Vrms= (3RT/M)^0.5........2
where R is universal gas constant ;T is temperature in kelvin and M is mass of a mole of substance in grams.
while calculating root mean square velocity, we get that it is inversly proportional to mass of gas. while in calculation of kinetic energy when we take sqaure of Vrms (as per the formula 1) the mass term gets cancelled out . Hence KE energy does not have a mass term . This does not mean that it is independent of mass.