# Area of a Disk

In this exercise we measure the radius and the area of 10 different disks. The purpose of the exercise to determine the relation between radius and area.

Procedure:

• Use the ruler to measure the radius of each disk (units: mm).
• Make an outline of each disk on the graphing paper supplied and determine the area of each disk by counting the number of squares enclosed by outline of each disk (units: mm2).
• Enter the measured values of the radius and the area of each disk in the table below.
• Change the parameters plotted on the horizontal and vertical axes until a linear relation emerges. Note: you must select the update button after each parameter change to update the graph and ratios.
• Determine the slope of the observed linear relation.
• What is the relation between the area and the radius of a disk ?

Note: the open button will not work when you use this applet on the WEB. You must use a stand-alone applet viewer for this feature to work.

Send comments, questions and/or suggestions via email to wolfs@nsrl.rochester.edu.