Question

To go from your house to a nearby hospital, you must walk 11 m E and then turn 13 m 63º S of W. What is your displacement? Use graphical (parallelogram method) and trigonometric method.

Answer 1

Trigonometric:

$$D_E=11-13\cos63°=5.1\text m.\\ D_N=0-13\sin63°=-12\text m.\\ D=\sqrt{D_E^2+D_N^2}=13\text m.\\\space\\ \theta=\arctan\frac{D_N}{D_E}=70°\text{ S of E}.$$