Two molecules of a gas have speeds of 9×106ms−1 and 1×106ms−1respectively. What is the root mean square speed of these molecules?

For n-molecules, we know thatvrms=v12+v22+v32+⋯+vn2n                   vrms= root mean square velocity where v1,v2,v3…,vn,are individual velocities of n-molecules of the gas.For two molecules,vrms=v12+v222 v1,v2⋅v3…,vn are individual velocity  Given, v1=9×106m/s and v2=1×106m/s∴ vrms=9×1062+1×10622=41×106m/s