posted by Lor .
a ferry is crossing a river. If the ferry is headed due north with a speed of 2.5 meters per second relative to the water and the river's velocity is 3 meters per second to the east, what will the boat's velocity be relative to earth?
X = hor. = 3m/s.
Y = ver. = 2.5m/s.
tanA = Y / X = 2.5 / 3 = 0.8333,
A = 39.8 deg.
Vb = X / cosA = 3 / cos39.8 = 3.9m/s.
@ 39.8 deg.