PASCO Specialty & Mfg. DISCOVER DENSITY SET SE-9719 Manual De Usuario

012–07192A

Discover Density Set 

and height.  Since it is difficult to analyze data from experiments in which

more than two variables, you group the cones into two groups.  One group

all have the same height, and the other group all have the same diameter.

Two others did not fit in either group.  Measuring the cones gives the

following results:

Group One are all 2.0 cm in diameter

3.0  cm

  5.56 g

4.0  cm

  7.41 g

5.0  cm

  9.27 g

6.0 cm

11.12 g

Group Two are all 2.0 cm tall

2.0  cm

  3.71 g

3.0  cm

  8.34 g

4.0 cm

14.83 g

5.0 cm

23.17 g

Cones not in either group above

“A”: 1.0 cm

4.0 cm

1.85 g

“B”:  1.0 cm

6.0 cm

2.78 g

Group 1 and 2 each relate mass, which may be thought of as the dependent

variable, to another variable that influences the mass.

Graphing the data from group 1, placing mass on the vertical axis, and

height on the horizontal axis, we obtain a straight line that passes through

the origin.

This form of graph shows that  y = m x,  where y is the variable plotted on

the vertical axis, and x is the variable plotted on the horizontal axis.  “m” is

the slope, which is constant.  The value of  “m” could be determined, to

complete the equation.  In this case, we do not need this much information.

It is enough for us to see that   y is proportional to x, or, in this case, that

Graphing the data of group 2 does not generate a straight line.  The shape of

the graph suggests an equation of the form y = c x

k

, where and k are

constants.  This hypothesis may be tested, and the constants evaluated using

any of the three methods described previously in the fluorite example.