Manipulating of formulas?

Question

Is there a site where i can read up or get more information on this, The formulas that I am having problems with is in the engineering field. (Angular motion, stress and strain and so on)

Answer 1

you can try wikipedia:

http://en.wikipedia.org/wiki/Rotation_ar...

http://en.wikipedia.org/wiki/Stress_(phy...

Answer 2

Perhaps you want to read about dimensional analysis, it makes manipulating most formula easy.

In case you are not familiar: Dimensional analysis is a conceptual tool often applied in physics, chemistry, and engineering to understand physical situations involving a mix of different kinds of physical quantities. It is routinely used by physical scientists and engineers to check the plausibility of derived equations and computations. It is also used to form reasonable hypotheses about complex physical situations that can be tested by experiment or by more developed theories of the phenomena.

Basically it is used to check that you have an equation, with actual measurements, correct. Write all the units down, and cancel and combine them, and the result should have the correct units for the answer.

Or if you are unsure how to combine measurements to get the answer desired, arrange the elements of the calculation so that the units combine to form the desired result.

take an example.

Specific heat has units of J/(g·K). I have one quantity of energy in 10 J, a temperature in 5C (same as K) and a weight in 15 grams.

So if I take the energy and divide it by the temp and weight, I'll get the correct units.

or

10J / (5C*15g) = specific heat in J/(g·K)