September 13, 2016 Professor M. Broccio Physics 0110 Video Module 2 2.1 Displacement 2.1.1 Position Is represented by a vector, r that is drawn from the origin of the coordinate system to a point on the coordinate system. (00.13) 2.1.2 Displacement A vector that points from the initial location to the ▯nal location; the di▯erence between ▯nal position and initial position (01:20) ▯r = r ▯ r0 (1) 2.1.3 Distance vs Displacement ▯ The di▯erence between distance and displacement is that distance measures the entire length of the path taken in order to get from point A to point B, while displacement is a measure of the di▯erence in position between point A and point B, regardless of the path that was taken to move from point A to B. ▯ For example, let’s say a swimmer dives o▯ the starting block in a 50m (olympic-sized) swimming pool, and swims two laps. When she ▯nishes, she swam a distance of 100m (from the block to the other end, and back.) However, her displacement is 0m, since she is at the exact same point as where she started. ▯ See also the maze example at 2:59 of video 2.1 2.2 Speed and Velocity 2.2.1 average velocity The average rate of change in position per unit of time ~ r ▯ r0 ▯r vavg= t ▯ t0= ▯t (2) 1 2.2.2 Instantaneous Velocity The instantaneous rate of change in position