Posted by **Tom** on Saturday, September 30, 2006 at 4:44pm.

In unit-vector notation, what is the sum of vector a =(4m)i + (3m)j and vector b= (-13m)i +(7m)j?

a)I got (27m)i +(10m)j but the book said it should have been (-9m)i +(10m)j

b)what is the magnitude and direction of vector a + vector b (relative to i)?

to find the magnitude i did the sqrt((-9^2 + 10^2) and then I got 13.453

I wasn't sure how to find the direction.

I am wondering how you got 27i? The i component of a was 4, and the i component of b was -13. Adding them gets the book answer.

Magnitude of the sum: (-13)^2 + (10)^2= 269, and the square of that is ....

Direction: arctan (10/-13)

jytttttttttttttttttttttttmhg

## Answer This Question

## Related Questions

- Physics - The two vectors a and b have equal magnitudes(on an x-y plane vector a...
- calculus - State whether or not the following statements are true. Justify your ...
- physics - Vector vector A has a magnitude of 6.90 units and makes an angle of 46...
- Physics - The three vectors have magnitude a =3m, b= 4m and c=10m . On the x ...
- Math - vectors - In the product F(vector)=q(V(vector)xB(vector), take q = 4, V(...
- Physics - Part A of this question asks for the sum of vector A = 3x+5y and ...
- Physics - Let vector A = 4i^ + 4j^, vector B = -2i^ - 5j^, and vector F = vector...
- Physics - Let vector A = 4i^ + 4j^, vector B = -2i^ - 5j^, and vector F = vector...
- phy - a watermelon seed has the following coordinates: x= -5.0, y = 8.0m, and z...
- Physics - The x component of vector A is -25 m and the y component is 40m a) ...

More Related Questions