Speed of a Bubble Lab
Purpose: To determine the speed of the rising bubble in each of the
three bubble tubes (blue, red and green).
Materials:
• Speed of bubble tube set
• Meter stick
• Ruler
• Stopwatch
• Calculator
• Graph paper
• Colored pencils
Procedures:
1. Start with the tube that is at your lab station. You will switch
with other groups to assure that you get to use each of the three
different colored tubes for the lab.
2. Measure the length of the tube in centimeters. Start inside of
the plastic cover at the end of one tube and measure to the
inside of the plastic cover at the other end.
3. Record the distance in centimeters at the top of your colored
tubes data table on the back of this page.
4. Hold the tube not quite horizontal, so the bubble is at one end.
5. Time how long it takes the bubble to rise from the bottom of the
tube to the top of the tube, when the tube is held vertically.
Record the time in the appropriate data table.
6. Repeat steps 4 & 5 four more times and record all data.
7. Average the five times for your tube by taking the total of ALL
of the trials and dividing them by 5. Record the average time for
your tube in the correct location.
8. Choose a time (at least 1 second, but shorter than the total time
it takes the bubble to reach the top).
9. Hold the tube not quite horizontal, so the bubble is at one end.
10.Have the timer ready with the stopwatch. When your partner says
GO, quickly hold the tube upright. Move one finger along the
tube, keeping it next to the bottom of the bubble. When your
partner says STOP, stop moving your finger.
11.Keep your finger in this spot while your partner measures the
distance from were the bubble began to your finger (in cm with
one decimal place ex. 6.4cm).
12.Record the EXACT time and distance in the appropriate data table.
13.Repeat steps 8-12 nine more times using different times. Use a
wide variety of times, including long and short times.
14.Repeat steps 1-13 for the other colored tubes. Be sure to record
all data in the appropriate data tables. Take turns being the
timer and the person in charge of the tube.
Speed of a Bubble Lab
Name ___________________________________
Partner(s) ______________________________
Data:
Blue Tube =
cm
Time to travel entire tube
Trial
1
2
3
4
5
Average
Time (s)
Red Tube =
cm
Time to travel entire tube
Blue Tube
Trial
1
2
3
4
5
Average
Time (s)
10 Random Times
Time(s)
Distance(cm)
Green Tube =
cm
Time to travel entire tube
Red Tube
Trial
1
2
3
4
5
Average
Time (s)
10 Random Times
Time(s)
Distance(cm)
Green Tube
10 Random Times
Time(s)
Distance(cm)
Analysis:
1. Plot the data from the lab on a line graph. Be sure to include
all of the components necessary for a line graph (title, correct
labels on the axes, correct scale and a key). Graph all three
sets of data on one graph (you should have 11 points for each of
the 3 colored tubes).
2. When the graph is complete, use the appropriate colored pencil to
make a line of best fit for each data set. Remember that a line
of best fit is one that represents the pattern of data. The
pattern should be a straight line, so use a straight edge. Your
line should start at the zero mark and continue upward.
Conclusions:
1. How far did the bubble in the blue tube travel in 6.5 seconds?
(To answer this, find the point on the best-fit line that is
exactly above the 6.5-second mark on the bottom of the graph.
Then trace horizontally to the left side to find the distance.)
2. How far did the bubble in the red tube travel in 6.5 seconds?
3. How far did the bubble in the green tube travel in 6.5 seconds?
4. In which tube was the bubble the fastest?
5. Which tube had the steepest graph?
6. Explain the connection between your answers to questions 4 & 5?
7. Explain why a line of “best fit” was the best type of graph to
use for this collection of data.
In the field of math, we often use the word “slope” when we want to
use numbers to say how steep something is. Slope is defined as Rise
divided by Run. Rise is the vertical measurement, and Run is the
horizontal measurement.
8. Find the slope of the graphed line from the blue tube.
a. Mark two points on the line, label them “A” and “B.” The
points should be on the line, and far apart. Try to choose
points that will make it easy to read the distance and time
measurements.
b. Point “A” corresponds to a distance of __________, and a
time of __________.
Point “B” corresponds to a distance of __________, and a
time of __________.
c. Use your answers from part “b” above to calculate the rise
and run:
Rise (y-axis) = __________cm - __________cm = __________cm.
Run (x – axis)= ___________s - ___________s = ___________s.
d. Now calculate the slope of line:
*Slope = Rise divided by Run = __________cm/s.
9. Follow the steps for number 8 above to find the slope of the
graphed line for the red tube.
Rise = __________cm - __________cm = __________cm.
Run = ___________s - ___________s = ___________s.
*Slope = Rise divided by Run = __________cm/s.
10.Follow the steps for number 7 above to find the slope of the
graphed line for the green tube.
Rise = __________cm - __________cm = __________cm.
Run = ___________s - ___________s = ___________s.
*Slope = Rise divided by Run = __________cm/s.
11.In the calculations above, you divided rise by run. The rise was
a distance, and the run was a time. “Distance divided by time “is
the formula for calculating _______________.
12.The slope of a distance vs. time graph is the _______________ of
the moving object.