Question

An electronic tracking device is placed on a police dog to monitor its whereabouts relative to the police station. At time t1 = 23 minutes, the dogs placement from the station is 1.2km, 33 degrees north of east. At time t2=57 minutes, the dog's displacement from the station is 2.0km, 75 degrees north of east. Find the magnitude and direction of the dog's average velocity between these two times.

Answer 1

To get the coordinates of each point you can use:
(x1, y1) ---> x1=r1*cosA, y1=r1*sinA
(r1 = 1.2km, A = 33deg)
(x2, y2) ---> x2=r2*cosB, y2=r2*sinB
(r2=2.0km, B = 75deg)
The displacement is:
d = sqrt[(x2-x1)^2 + (y2-y1)^2]
The direction of the resultant, angle C is:
C = tan^-1[(y2-y1)/(x2-x1)]
(C is measured from the positive x axis)
***Other trigonometric methods are possible or a scale diagram.