Finding the magnitude of the resultant vectors

[fxsnowy]

I need help on how to solve this

Homework Statement

Three vectors, expressed in Cartesian coordinates are :
S -> x( -3.5), y(+4.5)
T -> x(0), y(-6.5)
U -> x(+5.5), y(-2.5)

what is the magnitude of the resultant vector S + T + U?

The answer, according to my answer sheet is 4.9, but I don't know how to get that answer.

Any help is greatly appreciated

 

[member 392791]

What is the magnitude of a vector?

 

[rock.freak667]

Firstly, how would you go about adding one vector to another?

 

[Angela160290]

Solution.

There might be different ways to do it but here's how I did it.

First, add up all of the x values: (-3.5) + 0 + 5.5 = 2
then, add up all of the y values: 4.5 - 6.5 - 2.5 = -4.5

Then, use the pythagorean theorem on the absolute value of x and y (disregard the negative signs).

c^2 = a^2 + b^2
c = sqrt(a^2 + b^2)
= sqrt(2^2 + 4.5^2)
= sqrt(4 + 20.25)
= sqrt(24.25)
= 4.9