Solving Relative Velocity Problems

Relative velocity refers to the velocity of an object relative to the reference frame of the observer.

When a boat heads directly across a river, the resultant velocity is found by using the Pythagorean theorem to combine the boat's velocity and the river's velocity; the direction is found using trigonometry.

Perpendicular components of motion are independent of each other, meaning the river's southward velocity does not affect the time it takes for a boat to head eastward across the river.