two dimensional kinematics
posted by ringo .
A jetliner with an airspeed of 1000 kmlhr sets out on a 1500 km flight due south. To maintain
a southward direction, however, the plane must be pointed fifteen degrees west of south. Ifthe
flight takes 1 00 min, what is the wind velocity?

if the wind speed is s, set up the x and ycomponents of the vectors:
first, work with velocity vectors only.
1500km in 100 min = 900km/hr
so, using the law of cosines,
s^2 = 1000^2 + 900^2  2(100)(90)cos30°
s = 1340 km/hr