User's Manual

Discover Density Set 012–07192A

5. Determine an equation that represents the data. Use one or more of the

methods outlined in the previous examples. Your instructor may tell

you which method(s) to use. It is not necessary to evaluate the constant

in the equation at this time.

Procedure (Group 2)

1. For the other group of cylinders, create a table to record the length and

mass of each. The diameter of each cylinder in this group should be the

same. Record the length in centimeters. If you are using a metric ruler,

estimate to the nearest 0.01 cm when finding these dimensions. Use the

rules regarding significant figures or other appropriate methods of

expressing uncertainty.

2. Consider the length to be the independent variable, and the mass to be

the dependent variable when graphing the data. Prepare a graph that

shows the data for all four cylinders.

3. Draw a best-fit line for the data. If it is not possible to represent the data

well with a smooth line, recheck your measurements for any data points

that do not fit the pattern.

4. State a hypothesis regarding the form of equation that is likely to best

describe the data.

5. Determine an equation that represents the data. Use one or more of the

methods outlined in the previous examples. Your instructor may tell

you which method(s) to use. It is not necessary to evaluate the constant

in the equation at this time.

6. Now combine the equations that you have developed for the two

groups of cylinders. You may follow the example entitled “The mass of

cones.” At this time you should evaluate the constant in the equation,

including dimensional units.

Analysis Verification

Check the accuracy of the equation you have developed by using the

following data from published sources:

volume of a cylinder = π r

radius = diameter/2

density of the cylinder material = 1.42 g/cm

density = mass/volume

Algebraically combine this information to produce an equation giving the

mass of these cylinders in terms of their diameter.

Compare this result with the equation you determined experimentally. Are

they in agreement, taking into account uncertainty?