Chapters

 Page 5

This text is meant to accompany class discussions. It is not everything there is to know about uniform circular motion. It is meant as a  prep for class.

Click for the questions that go with this reading
Calculating the slope

Below is a YouTube video showing how to find the slope.

This YouTube video is located at http://youtu.be/wbQoeel9hHo

 Slopes are positive or negative

 Slopes have units

This YouTube video will show you how to calculate the slope's units.

This video can be found on YouTube at http://youtu.be/1pd6qL_DDaI

 The equation of a stratight line on a graph is expressed in slope-intercept form.

 y = mx + b y = y-coordinate for a point on the line. x = x-coordinate for the same point on a line m = slope b = y-intecept ...where the line crosses the vertical axis For the example graph above, the equation is It would be tempting to look at the graph and call the y-intercept 2. The problem with this interpretation is the fact that the graph’s horizontal numbers do not start at zero. Therefore the axis at the left is not the y-axis. The y-axis is where x = 0.
Calculating the y-intercept

To calculate the y-intercept, use y = mx +b and solve for b. Pick ANY point on the line to find x and y. Calculate the slope as shown above. Plug these values into y = mx + b and solve for b.

 Example EXAMPLE: from the graph above. x= 60, y = 10 (that’s the first point on the graph, from the data) and m = 4/25. Therefore the correct equation for the line is

by Tony Wayne ...(If you are a teacher, please feel free to use these resources in your teaching.)