A boater wants to head straight across a river that has a current of 3 km/hr. If the top speed of the boat in still water is 4 km/hr. 1.find the direction the boat must travel into the current to go straight across the river?

Question

2. How fast is the boat going straight across the river?

Another boat with a bigger motor wants to cross the same river at the same point but wants to travel at a constant 4 km/hr rate.

3. What angle does the boat head into the current and how fast is the boat going with respect to the water around it?

Answer 1

1. Vr = Vc + Vb = 4.
-3i + Vb = = 4, Vb = 4 + 3i = 5km/h[36.9o].
Direction = 36.9o N. of E.

2. Vr = 4 km/h. = Resultant velocity.

3. 5km/h[36.9o].