Determine the magnitude ad direction of the vector

1. Sep 16, 2007

innightmare

I am not sure on how to approach this problem:
Question:
Vector A has a negative x component 3.00 units in length and a positive y component 2.00 units in length.
a) Determine an expression for A (vector w/arrow hat)in unit-vector notation.
b)Determine the magnitude ad direction of A
c)What vector B When added to A gives a resultant vector with no x component and a negative y component 4.00 units in length?

Can you please give me pointers on how to tackle problems such as these as well as what books/solutions/or things I should do, besides from studying, that will HELP me understand physics.
Thanks!

2. Sep 16, 2007

mjsd

New to PF? well, questions llike this should probably goto the homework forum... anyway, welcome aboard.

Re: Vectors
you are given the x, y porjections of your vector, you are asked to
a) write your vector A in terms of unit vectors for you coord system (probably x, y-axis) so wanna express $$\vec A = a \hat{\vec x} + b \hat{\vec y}$$ where $$\hat{\vec x}, \hat{\vec y}$$ are the unit-vectors in x, y direction. then u r asked to find $$|\vec A|$$ length of vector and direction (probably means the angle it makes with the positive x-axis). Length of vector you need Pythagoras.
finally, you are asked to do some vector addition, since you have been given the x, y -comp, that's make it easy to find the required vector B (in component form), and then you can repeat the steps in a) and b) to find things like magnitude and angle for B.

3. Sep 24, 2007

elprospero

effects of unequal charges on protons and electrons

The charges on the proton and the electron have been found to be equal to a great many decimal places. But what would be the most important result if the charge on the electron were very slightly less than its measured charge? Wasn't there once a theory of gravitation based on this (assumed) difference?
Elprospero@dslextreme.com