Walking a D vs. t Graph

Purpose: To graphically demonstrate motion.

Procedure: 1. Write a “plan” on how you will move. Walk only along a straight-line path. During your walk there must be a least one time where: you are at rest, you change directions, you speed up, you slow down, & you walk at a constant rate in both directions. Note for how long you plan to do each motion. Your plan must describe 30 seconds of motion. i.e. I am going to not move for the first 6 seconds, then I will walk forward at a constant rate for 6 seconds, I will then walk backwards while speeding-up…. 2. Number your poker chips from 0-31. 3. Walk your “plan”. Keep time just by counting aloud (1-one thousand, 2 – one thousand, …). Mark where you are at the end of each second by dropping your poker chips in order Hints:  Figure out some way to drop the chip so that it does not move from the spot where it lands.  Make all motions last at least 4(6 is better) seconds or longer so that you can see the pattern when you graph the motion.  When you are speeding up you will be tempted to count faster and when you are slowing down you will be tempted to count slower. Don’t. To speed up (or slow down) don’t try to take more (or fewer) steps in a second, just plan on taking larger (or smaller) steps.  Make sure you speed up while walking. Don’t just suddenly walk faster, but instead make each step a little bigger than the last so that with each step you are getting faster.

Data: This will be a table of the chip number (= time) and the displacement to each chip. Your origin is where the 0 chip is; measure all distances from the origin. Recall that displacement can be negative. If you move behind your origin these distances must have a negative sign.

Analysis

Make a graph of displacement vs. time. Have a best fit line for each type of motion (using colored pencils for each is nice). Two of these should be curved, however, if you did not maintain the motion long enough, it might not be that obvious.

Conclusion:

Describe how each of the different types of motion (at rest, speeding up, slowing down, traveling at a constant speed both forward and backward) is represented on a d vs. t graph.