# Homework Help: Physics test help

1. Apr 22, 2004

### Maxwell

Hey, I have a test tomorrow and though I understand most of what is on the test, Fluid mechanics is giving me some problems. I've read the chapter through and have a few questions.

1) When they say Bernoulli's equation is $$\frac{1}{2} \rho V^2 + P{o} + \rho g h = constant$$ or anything else for that matter, what does constant mean? When do I set it equal to itself? What can I do with it being equal to constant?

2) What is the equation of continuity for fliuds? How is it useful?

And I have 2 sample problem which would fantastic if you guys could show me how to solve them? That way I can print out the post and head to the library and go over the problems and try them myself.

Here they are:

1) A large storage tank, open at the top and filled with water, develops a small hole in its side at a point 16.0m below the water level. If the rate of flow from the leak is equal to 2.50 x 10^-3 m^3 per min(sorry i can't get the TeX working for this), determine (a) the speed at which the water leaves the hole and (b) the diameter of the hole.

2) A piece of aluminum with mass 1.00 kg and density 2,700 kg/m^3 is suspended from a string and then completely immersed in a container of water. Calculate the tension in the string (a) before and (b) after the metal is immersed.

Thank you in advance. I am going to the library to study for a couple of hours, so I will come back and check the website when I return to my room. Then I'll head back to the library to study fluids, lol.

The test is on angular momentum, static equilibrium, universal gravitation, fluid mechanics, and oscillatory motion, so any pointers on those topics you can throw in would be great. Thanks.