posted by tonda on .
A car travels along a straight road, heading east for one hour then traveling for thirty minutes on another road that leads northeast. If the car has maintained a constant speed of forty miles an hour, how far is it from its starting position
X = hor = 40 mi/h * 1 h + 40 mi/h * 0.5 h * cos45 = 40 + 14.1 = 54.1 mi.
Y = ver = 40 mi/h * 0.5 h * sin45 = 14.1 mi.
tanA = Y/X = 14.1 / 54.1 = 0.2606,
A = 14.6 deg.
d = x / cosA = 54,1 / cos14.6= 55.9 mi.
from starting position.