1. The problem statement, all variables and given/known data What is the root mean square speed of Helium at 5K? 2. Relevant equations Vrms=sqrt((3kbT)/m) 3. The attempt at a solution I plugged all the numbers in and keep getting 7.19*10-12. The computer keeps telling me that it is not correct. The next question ask for the avg KE which I found to be 1.04×10−22. I tried using 2/3 Kavg/kb and got 7.21*10-12. The computer tells me that is wrong also. Where am I messing up?