Hey guys,

One thing I found really challenging on my first practice test was the expectation of doing alot of mental math. I was completely boggled when they expected me to do calculations involving Joules ->eV, or for instance, Problem 22, ending up having to take the square root of: v = sqrt(6480*.4*g). How would i ever do that? I mean I guess 6400000 is like 8000, and root(g) is like root(10), but I have no idea what sqrt(.4) would be, and my final answer would look like: v = (8000)(sqrt(10))(sqrt(.4)), how do I get 3.6km/s out of that?!

Any tips would be appreciated.

Ari

I realize there are other ways to do this problem, but the bottom line I'm wondering is - is it up to you to come up with the best method in under 2 minutes so that you don't have to use a calculator, or are there some general calculator guidelines I should remember?