RMS Speed?

[weeeman]

Got a question on a past paper and completely forgot how to do it.

3 particles have speeds 935m/s 743m/s and 312m/s. Calculate rms speed.

 

 

Can anyone help

[elfmotat]

Square each speed, add them together, divide by 3, then take the square root.

 

[math]v_{rms}=\sqrt{\frac{1}{n}\sum_{i=1}^n (v_i)^2}[/math]

 

where v_i is the speed of the i'th particle (i.e. i=1,2,3...) and n is the number of particles.

[weeeman]

thank you very much. I am lucky enough to have the markscheme and so i can see this is correct although i will not have the markscheme in my exams which is a little problem haha