Log in

View Full Version : Physics and Vectors


sGt HarDKorE
Nov 7, 2009, 11:08 AM
I have a question on what to do with this physics problem. I have tried looking up help on Google but can't find a straightforward answer. Let me first describe the graph. There are 3 vectors, in the shape of a 'Y'. One is going NE, one NW, and the last going South. I am suppose to use the graphical method to find the resultant, but where do I begin with this problem?

Unknown008
Nov 7, 2009, 11:21 AM
There are two ways of doing that.
1. Break down two of the vectors into parallel and perpendicular vectors to the last one. Then, cancel the vectors which cancel out. You'll have 2 last vectors, each perpendicular to each other, which you can find the resultant easily.

2. Find the resultant of two vectors. Then, find the resultant using the third vector and the first resultant.

I hope it helped! :)

sGt HarDKorE
Nov 7, 2009, 11:48 AM
Thanks! Question on the first choice. If you have 3 vectors and I cancel out 2 like you said, wouldn't that leave me with one, not two like you said?

Nhatkiem
Nov 7, 2009, 12:15 PM
Thanks! Question on the first choice. If you have 3 vectors and i cancel out 2 like you said, wouldn't that leave me with one, not two like you said?
No no essentially what you are doing are adding two vectors by their vertical and horizontal components and getting the resultant vector to represent two vectors as 1 vector. Then you are left with 2 vectors :o

Perito
Nov 7, 2009, 03:53 PM
Don't confuse yourself.

Calculate the horizontal and vertical component for two of the vector segments. Add the horizontal components (some may be negative, some may be positive). Add the vertical components. Use trigonometry to figure out the resultant vector (the hypotenuse of the right triangle with the horizontal and vertical components as sides) and you have the final resultant vector. You now have one resultant vector for two of the vectors. Repeat the calculation with the new vector and the remaining vector in your set. This will give you a final resultant vector.