Problem 3-9 - Vector sum - Part 7 (b)

Find the magnitude and direction of the sum of the vectors \(A + B + C\) using the component technique. Assume two significant digits.
\(A = 20\; km\) north, \(B = 30\; km\) east, \(C = 50\; km\; 55 ^\circ\) west of north.


Accumulated Solution

graph indicating magnitude of direction (b)

Variable \(x\) comp \(y\) comp
A \(0\) \(+20\)
B \(30\) \(0\)
C \(-50 \cos 35^\circ = -41\)  \(50 \sin 35^\circ = 28.7\)
Sum \(30 - 41 = -11\) \(20 + 28.8 = 48.7\)

Correct!

We have now assembled all the \(x\) and \(y\) components. The sum is shown in the table above.
 

The magnitude of \(R\) is given by:

(A)   \(R_x + R_y\)

(B)   \((R_{x^2} + R_{y^2})^{1/2}\)

(C)   \(R_y/R_x\)