1. ## vector problem

A river flows through the jungle from west to east at a speed of 3 km/h. An explorer wishes to cross the river by boat, and attempts this by travelling at 5 km/h due north. At what bearing should the boat travel so that it arrives at the opposite bank of the river due nort of the starting position?

2. Originally Posted by Mr Rayon
A river flows through the jungle from west to east at a speed of 3 km/h. An explorer wishes to cross the river by boat, and attempts this by travelling at 5 km/h due north. At what bearing should the boat travel so that it arrives at the opposite bank of the river due nort of the starting position?
make a sketch ...

$\theta = \arcsin\left(\frac{3}{5}\right)$

bearing would be $\theta$ degrees west of north

3. How come the 5 is on the diagonal? Shouldn't it be on the vertical line?

4. Originally Posted by Mr Rayon
How come the 5 is on the diagonal? Shouldn't it be on the vertical line?
the boat travels at 5 km/hr relative to the river.