Solving Relative Velocity Problems

I can solve problems involving relative velocity in two dimensions.

9:58

We don't generate video — this one is by The Physics Classroom on YouTube. The practice questions and exit ticket below were drafted by AI for this objective, and every question is editable in the teacher guide.

1. 1

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

2. 2

   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.

3. 3

   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.

“A boat travels east across a river with a velocity of 6 m/s with respect to the water. The river is flowing south at a velocity of 2.5 m/s with respect to the shore. What is the magnitude of the resultant velocity of the boat with respect to an observer on the shore? Show your work.”

Sample answer included in the free materials