Video
Supplements: Sea
Can Your Boat Float?
Overview
Students build several boats using aluminum foil, measuring
the length and width of the bottom of the boat. They then
see how many pennies it takes to sink the boat and determine
if the area of the bottom makes a difference.
Outcome
Students will apply knowledge of perimeter and surface
area, plus they will gain an understanding of the concept
of buoyancy.
Standards Addressed — Mathematics
Grade
4
Use Measurement Techniques and Tools, Benchmark D
04. Develop and use strategies to find perimeter using
string or links, area using tiles or a grid and
volume using cubes; e.g., count squares to find area
of
regular or irregular shapes on a grid, layer cubes
in a box to
find its volume.
Grade 5
Measurement Units, Benchmark F
03. Demonstrate and describe the differences
between covering the faces (surface area) and
filling the
interior (volume)
of three-dimensional objects.
Grade 6
Measurement Units, Benchmark F
01. Understand and describe the difference
between surface area and volume.
Use Measurement
Techniques and Tools, Benchmark G
05. Understand the difference between
perimeter and area, and demonstrate that two
shapes may have the
same perimeter,
but different areas or may have the
same area, but different perimeters.
Standards
Addressed — Data Analysis
Grade 4
Data Collection, Benchmark C
02. Represent and interpret data using tables,
bar graphs, line plots and line graphs.
Grade
5
Data Collection, Benchmark E
02. Select and use a graph that is appropriate
for the type of data to be displayed;
e.g., numerical vs. categorical
data, discrete vs. continuous data.
Grade
6
Data Collection, Benchmark E
02. Select, create and use graphical representations
that are appropriate for the type of
data collected.
Standards Addressed — Physical
Science
Grade 3
Forces and Motion, Benchmark C
04. Predict the changes when an object experiences
a force (e.g., a push or pull, weight and
friction).
Grade 6
Nature of Matter, Benchmark A
01. Explain that equal volumes of different
substances usually have different masses.
Materials
Procedure
-
Break students into groups
of two or three.
-
Demonstrate the concept of building
a boat by bending the foil.
-
Have the students cut three
16 cm squares from the foil and create
a flat-bottomed
boat with each
piece.
Instruct
the students to vary the sizes
of the boats.
-
Have the students write a
hypothesis about what they
think will happen.
-
Students can trace the bottom
of their boat using centimeter
graph paper
(provided
with
this guide)
or a ruler. Students
find the closest measurement
for the area of the bottom
of the boat. (If
the boat
is rectangular,
triangular
or circular, students can simply
use the measurements and
apply the formula to find the
area of the bottom of the boat.)
-
They
place the boat in a container half-full of water
and add pennies
to it until the
boat sinks.
They should
include the penny that sank
the boat in their count.
-
Each group should record the area of the bottom of
the boat
and the number
of
pennies
required
to sink the
boat
on the student handout. Students
should be sure that they
measure using square
centimeters.
-
Have the students
make two more models of boats
and do
the same experiment
with
each
model.
-
They then construct
a graph with area on the
x-axis
(independent
variable)
and
number
of pennies
(dependent
variable) on the y-axis.
-
Reviewing
their results, students can make an observation
of what worked
best.
They should
come up with the conclusion
that the bigger the area,
the more pennies it will hold.
-
Be sure to mention
that when measuring the bottom of the boat, we are
using part of
the
surface area
of the boat.
The
water that
would fit inside
the boat
is a measure of the volume of the boat.
-
It
is important to make sure that the students understand
the science behind this
experiment.
The science concept involves
buoyancy.
When
a boat sits in
the water, it is pushing the water aside
and pushing downward. The water is pushing
up on the bottom and the sides of the boat.
The more water that the boat pushes aside,
the more
water
that is pushing
back on
the boat
and keeping
it afloat.
This is why the size and shape of the boat
are important.
-
Extension #1: Try this same
experiment using 32 cm squares of foil.
-
Extension #2: Try adjusting the placement of the pennies. Determine
the effect
of stacking the
pennies
or spreading
them out.
-
Extension #3: Assign the task
of making a “flinker,” which
is something that will not float but
will not sink for at least 10 seconds.
A complete
lesson plan is at pbskids.org/zoom/activities/sci/flinker.html.
Student Handout Answers
View the Can
Your Boat Float? sample answer sheet.
Evaluation
Rubric for evaluating graph
Category
|
4
|
3
|
2
|
1
|
| Accuracy of Plot |
All points are plotted correctly and are easy
to see. A ruler is used to neatly make the bars,
if not using a computerized graphing program. |
All points are plotted correctly and are easy
to see. |
All points are plotted correctly. |
Points are not plotted correctly, or extra points
are included. |
| Labeling of x-axis |
The x-axis has a clear, neat label that describes
the units used for the independent variable. |
The x-axis has a clear label that describes the
units used for the independent variable. |
The x-axis has a label. |
The x-axis is not labeled. |
| Labeling of y-axis |
The y-axis has a clear, neat label that describes
the units and the dependent variable. |
The y-axis has a clear label that describes the
units and the dependent variable. |
The y-axis has a label. |
The y-axis is not labeled. |
| Title |
The title is creative and clearly relates to
the problem being graphed (includes dependent and
independent variables). It is printed at the top
of the graph. |
Title clearly relates to the problem being graphed
(includes dependent and independent variables)
and is printed at the top of the graph. |
A title is present at the top of the graph. |
A title is not present. |
|
