A dog searching for a bone walks 3.50 m south, then 8.20 m north of east, and finally 15.0 m west.

(a) What is the magnitude of the dog's total displacement?
(b) What is the direction of the dog's total displacement where directly east is taken as
zero degrees and counter-clockwise is positive?

2 answers

8.2 at NE = 5.8N and 5.8E

(0,-3.5)+(5.8,5.8)+(-15,0) = (-9.2,2.3)

(a) sqrt(9.2^2 + 2.3^2) = 9.48
(b) arctan(2.3/-9.2) = 166 deg
The answer for a is 7.9