ShowMe - Inclined Plane, Frictionless

Inclined Plane, Frictionless simulates the motion and forces acting on a mass moving down a smooth, frictionless incline.

This document shows you how to use this applet in a step-by-step manner. You should have the applet open; toggle back and forth between the ShowMe file and the applet as you work through these instructions.

1. Using the Ramp Angle Slide Control

First, move the Ramp Angle slide control between 0° and 90° to observe how the ramp and the mass (a 100 g box of crayons) move in response.
Next, press the "Play" control button - the box of crayons should begin to accelerate down the ramp.

2. Introducing Free Body Diagrams

To see a Free Body Diagram (FBD) for the box of crayons, press the FBD control button and select all three of the check box options. You also will see a forces information panel in the upper right corner that shows the sizes of the various forces and components relevant to this applet.

Try doing the following:

Move the FBD by positioning the cursor in the centre of the FBD. A green circle appears - you may now reposition the FBD by holding the left mouse control button down and dragging the FBD to any position on the applet display panel. If nothing is happening, make sure that you checked the Move FBDs option above.

Un-check the "Toggle Components" box by pressing the check box. A short-cut way of doing this is to right-mouse click anywhere in the drawing panel. The following menu will pop-up.

3. Numerical Examples

Adjust the ramp angle to 0°. You should see that both the normal force and the weight (force) are 0.98 N in magnitude.

Next, adjust the ramp angle to 47.3°. You should see the normal force drop to 0.67 N, but the weight, as expected, remains at 0.98 N. Your screen should look like the figure on the left.
The applet shows you the magnitude of the x- and y-components of the weight as well. You should experiment with the ramp angle to observe how these components change with a change in the angle.

4. Running the Applet

To run the applet, press "Play". You will observe the mass moving. Vary the ramp angle and note the effect that this has on the rate of acceleration of the box down the ramp.

5. Getting Graphical Output

A very powerful feature of any applet that makes use of the grapher is the ability to generate graphical output. To make sure that your applet will generate graphs, ensure that data collection is enabled. Click the Data Collection control button and make sure that "collect data" is selected. Now press the grapher control button and follow the steps listed below.

6. Example: Plot a Velocity-Time Graph

Open the X Axis selection menu and click on Time.

Open the Y Axis selection menu and click on Velocity.

Press the magnifying glass option to fit the v-t graph to the screen.

Use the Graph Tools - Slope and Area

The following two tools may be used to extract information from this graph:

Slope - a blue "slope-arrow" will appear at the origin of the graph. As soon as you move the cursor over the arrow it will become "active" and you can drag it along the curve. The value of the slope will be given in the upper-left hand corner of the grapher .

Area - now position the cursor at the origin of the graph, hold down the left-mouse control button, and drag the cursor along the x-axis. A green shaded region begins to grow between the velocity graph and the x-axis. The area of this region appears in the upper left-hand corner of the grapher.

7. Generating Data Tables for Export to a Spreadsheet

You can also export the data used to construct your graph(s) to a spreadsheet very easily by pressing the Data Options control button and then select generate table by pressing from the drop-down menu. At this point, you can either save the data as a text file or highlight it with the mouse and cut and paste this into a spreadsheet program.

Last Updated: June 16, 2004