A bird watcher meanders through the woods, walking 1.13 km due east, 1.01 km due south, and 3.95 km in a direction 49.8 ° north of west. The time required for this trip is 1.965 h. Determine the magnitudes of the bird watcher's (a) displacement and (b) average velocity.

Answer 1

a. D = 1.13km[0o] + 1.01km[270o] + 3.95km[130.2o] = (1.13+3.95*Cos130.2) + (1.01*sin270+3.95*sin130.2)i =
-1.42 - 1.009i = 1.74km[35.4o W. of S.].

b. D/t = 1.74km[35.4o W. of S.]/1.966h = 0.885km/h[35.4o W. of S.].