Introduction

The topic of relative motion is first introduced.  This involves defining some physics terms such as kinematics, scalars and vectors.  Next, an example of relative motion in one dimension is given.  The example of 2 vehicles traveling down a road with different velocities is a simple example to show.  This is then followed by an analysis of the situation.  An explanation is then given on how to find the relative velocities from different observers' frames of reference.

First Demonstration is a typical “river problem” in one dimension

Using my simulated river, a boat whose motion is upstream, is simulated.  The instructor and students then find all the relative velocities of the 3 objects (a person standing on the bank of the river, a boat, and a kayaker floating with the current of the river).

Introduction of two dimensions and relative motion

One more dimension is then added to the situation.  Now we can simulate at boat in motion upstream and across a river.  An example of a boat that is crossing a river is then given.  The location where the boat lands on the other side of the river can then be found.  The boat's motion is also found in different frames of reference.

Second and Third Demonstration

The second demonstration is a simulation of boat aimed directly across the river.  The resultant path of the boat is across the river and downstream.  With this simulation we can find the resultant motion of the boat.  With the third demonstration the goal is to aim the boat upstream so that the boat’s motion is directly across the river.  These demonstrations are should numerous times as they are more complex to understand.  In addition, the demonstration is stopped at different places to analyze the boat's motion.

Note

It is important to stop the demonstrations and analyze the situation.  When figuring out the velocity of an object, start by finding the direction, then the magnitude.  To get a better understanding of my lesson plan you can view the powerpoint presentation (PDF form).