# Using the Maxwell-Boltzmann distribution function to find specific molecule speeds?

I've been looking for problems to practice on this topic and found a problem asking to use the Maxwell-Boltzmann distribution function to calculate the fraction of Argon gas molecules with a speed of 305 m/s at 500 K. I thought the distribution function could only be used to find the fraction of molecules moving between two given speeds not at a specific speed. Can someone explain how to do this?

• You're right. The question expects you to find the fraction of molecules with speeds between $v$ and $v+dv$ (in terms of $dv$; there will be a factor of $dv$ in the answer). – Brian Moths Dec 7 '13 at 3:59
• @NowIGetToLearnWhatAHeadIs Thanks for clearing that up! – Logan Dec 7 '13 at 16:44