Question

A stream is 30. meters wide and its current flows southward at 1.5 meters per second. A toy boat is launched with a velocity of 2.0 meters per second eastward from the west bank of the stream
a. what is the magnitude of the boat's resultant velocity as it crosses the stream?
b. how much time is required for the boat to reach the opposite bank of the stream?

Answer 1

a. X = Hor = 2 m/s
Y = Ver = 1.5 vm/s,

tanA = Y/X = 1.5/2 = 0.75,
A = 36.9 Deg.
R = X / cosA = 2/cos36.9 = 2.5 m/s
= Resulting velocity.


b. d = 30 m / cos36.9 = 37.5 M,
d = v * t,
37.5 = 2.5t,
t = 37.5 / 2.5 = 15 s.

Answer 2

15