Bubble Lab

40 points

Purpose:    Using bubble diameters to determine the relationship between centimeters and inches.

 

Equipment:  Soapy water, Straws, Rulers (inches and centimeters)

 

Procedure:

1.      Make your lab table slightly soapy by pouring a small amount of bubble solution on the table.

2.      Use your straw to blow a bubble on the table.  Try to make it as large as you can.

3.      When the bubble pops, it will leave a soap ring on the table.  Measure the diameter of this soap ring in inches and centimeters and record the data on your data table.

4.      Repeat this process 5 times (I want you to blow and measure a total of 5 bubbles)

 

Data/Graphs:

1.      Copy the following data table onto a blank sheet of notebook paper:

 

 

                                                      Inches       (x)        Centimeters (y)

 

                               Bubble #1      __________in      __________cm

                               Bubble #2      __________in      __________cm

                               Bubble #3      __________in      __________cm

                               Bubble #4      __________in      __________cm

                               Bubble #5      __________in      __________cm

 

2.      Make a graph of the data.  Put inches on the x-axis and centimeters on the y-axis.

3.      Find the slope of the line you just created.  Remember that the formula for the slope of a line is:   y2 – y­1. 

                                                                                                                                                        x2 – x1   

      You need to find the slope between Bubble #1 and Bubble #2.  Between Bubble #2 and Bubble #3.  Between Bubble #3 and #4.  Between Bubble #4 and Bubble #5.

4.      Bubble #1 and the last Bubble on your data table (Bubble #5).  ARE ALL OF THESE SLOPES THE SAME?  THEY SHOULD BE!

 

Conclusion/Questions:

1.      Look at the following examples of some common conversions.  Then, fill in the blank for cm/inch.

3 feet                  1609 meters                12 eggs                     ? cm

1 yard                    1 mile                        1 dozen                  1 inch

 

2.      Now that you have decided how many centimeters are in 1 inch, how many inches are in one centimeter?

? inches

1 cm

 

3.      If you blew bubbles with the following diameters in centimeters, how big would they be in inches?  You need to show your conversion work and round to one number after the decimal point.

 

a.       16.0 cm     (answer:  6.30 inches)

b.      28.0 cm

c.       32.1 cm

 

4.      If you blew bubbles with the following diameters in inches, how big would they be in centimeters?  You need to show your conversion work and round to one number after the decimal point.

 

a.       18.0 in      (answer:  45.7 cm)

b.      25.6 in

c.       91.5 in

 

5.      On the back-side of your bubble graph, draw a graph of the following data.  Remember to label your x and y axis.  Connect the dots too!

 

                         Monkey Toenails (x-axis)                  lbs (y-axis)

                                          5                                             0.5

                                         20                                            2.0

                                         30                                            3.0

 

6.      What is the slope of this line?

 

7.   Fill in the following conversions:     ? Monkey Toenails   and    ? lbs________

                                                                      1 lb                                1 Monkey Toenail

 

8.  Your Uncle Billy leaves you 50 Monkey Toenails in his will (you were always his favorite).  How many pounds of toenails do you have?  Show your conversion work using either one of the conversions you discovered in question #7.