Posted by Rac on .
Two ships leave a harbor at the same time, traveling on courses that have an angle of 140 degrees between them. If the first ship travels at 26 miles per hour and the second ship travels at 34 miles per hour, how far apart are the two ships after 3 hours?

geometry 
Henry,
I drew the vector for ship # 1 @ 0 deg
and ship # 2 @ 140 deg.
d1 = 26 mi / h * 3 h = 78 mi @ 0 deg.
d2 = 34 mi / h * 3 h = 102 mi @ 140 deg.
d = 102 mi @ 140 deg  78 mi @ 0 deg.
X = hor = 102 * cos140  78cos0,
= 78.1  78 =  156.1 mi.
Y = ver = 102sin140  78sin0
= 65.6  0 = 65.6 mi.
d^2 = x^2 + y^2,
= 24367.2 + 4298.7,
= 28665.9,
d = sqrt(28665.9) = 169.3 miles apart.