Rewriting a Radical Function With Multiple Variables

[Human]

Hello everyone,
I was wondering if I could get some help with this problem:

It has stumped my older siblings and I...
Thanks in advance,
Human

 

[skeeter]

[MATH]B = \sqrt{\dfrac{68W}{3131}}[/MATH]

 

[Harry_the_cat]

Hello everyone,
I was wondering if I could get some help with this problem:
View attachment 25249
It has stumped my older siblings and I...
Thanks in advance,
Human

Interesting formula in that it mixes metric (sq metres) and imperial (inches, pounds) measurements. Are you sure the units are correct?