Calculating Slope of Distance vs Time
Slope is how steep or shallow a line is on a graph. Now that we know what which slope is faster, how can we know the actual number value for velocity (or acceleration)?
Velocity Reminder
Slope Equation
Slope is found by taking the difference in the y values and dividing it by the difference in the x values at the same points. The equation is very similar to the velocity equation, and is used the same way.
In the case of velocity,
|
How to calculate Slope on a graph
Here are the steps to determine the slope/velocity of a line.
- Pick two points on the line and determine their coordinates.(x,y)
- Determine the difference in y-coordinates of these two points (rise).
- Determine the difference in x-coordinates for these two points (run).
- Divide the difference in y-coordinates by the difference in x-coordinates (rise/run or slope).
Examples
More Complex Graphs
You can use the same way to determine the velocity at different sections of the graph. You can also get an overall acceleration.
Positive and Negative Slopes
Positive Slope on Distance vs Time Graph
Moving Forward |
Negative Slope on a Distance vs Time Graph
Moving Backwards |
Other Links
Practice
http://dev.physicslab.org/Document.aspx?doctype=5&filename=Kinematics_ConstantVelocityPositionTimeGraphs1.xml
http://dev.physicslab.org/Document.aspx?doctype=5&filename=Kinematics_ConstantVelocityPositionTimeGraphs2.xml
http://dev.physicslab.org/Document.aspx?doctype=5&filename=Kinematics_ConstantVelocityPositionTimeGraphs2.xml
Images from physicsclassroom.com