Any experts in physics out there?

[Molly]

i know this is a math forum, but I need help in the Kinematics section of Physics, as my test is on Monday!!!!!!!!!!! :shock: Does anyone know how you would go about adding and subtracting vectors? It sounds simple enough, but the testbook keeps telling me to graph these certain ( A, B, and R) vecors, and I don't know how to go about that ( which vector do I plot first, what angle shoud I use, what does the end result really tell me????????) Any information would be greatly appreciated...Thanks........

 

[pka]

You really need to post a particular problem!
You have suggested several possible difficulties.
With a specific problem someone can give you appropriate help.

 

[Molly]

I guess I'm in that range of people who don't understand binary numbers then .....What my original question was, was how do you subtract and add vectors?????? i was trying to give examples to try and help but as you can see from my mess of questions, I really don't know what I'm doing........please help............

 

[pka]

“What my original question was, how do you subtract and add vectors?”
Well O.K., then there is a simple answer to that question.
One subtracts and adds vectors component wise.
That probably does not help very much.
We have no way of knowing the level on which you are to be tested!
Please give us a particular problem.

 

[daon]

I dont know if this will be much help, but:

Generally if you are given two vectors say:
a. 3i + 3j
b. -6i - 8j
You can add them together graphically by drawing an arrow from the origin to point a (up 3, right 3), and then draw another arrow, down 6, left 8. Your resultant vector will be drawn form the origin to where the head of your last vector ends up.

The analytical way would be to just add the i components and the j components. So R = -3i -5j.

Hope I helped and didnt confuse you at all.