Transcript Parachute - Pinellas County Schools

Scientific
Thinking
© Pinellas County Schools 05-06
Science Inquiry Skills
• Observing, hypothesizing,
measuring, classifying,
collecting and interpreting
data, predicting,
experimenting, inferring
and communication
Topic Statement
• I am interested in
studying
________________
________________
sports?
weather?
animals?
Music sound?
plants?
I am interested in studying:
aerodynamics
parachutes
electricity
how lights work
force and motion
simple machines
plate tectonics
volcanoes
salinity of water
the ocean
convection currents cooking
chemistry
mixtures and
solutions
Science Content Statement
• Learn more
about your
topic from
the library,
internet,
textbooks,
and write
down what
you learned.
Parachutes
The main idea behind a parachute is that this device slows down a
falling object. It does this by creating a drag or air resistance. Air Resistance is a
frictional force experienced by objects as they move through air or as air flows
around them. It generally opposes the motion of the object or the air flow
around it, and is created by the air rubbing on the outside surface of the
object. When the parachute canopy is opened, the air molecules move farther out
creating drag. The more drag that is created the slower the object falls down.
The force acting on the falling object is gravity. Gravity is the force of
attraction between all masses in the universe; especially the attraction of the
earth's mass for bodies near its surface. If something or someone falls from the
sky gravity will quickly pull them to the Earth’s surface. A parachute is used to slow
this effect down.
The drag or air resistance depends on the surface area of the object. Surface
area is the measure of how much exposed area an object has. Parachute
canopies have large surface area which creates enough drag for its passenger.
Shapes also have an effect on the efficiency of the parachute. Modern designs have
rectangular or tapered shapes. Tapered parachutes are in parachute sports. They
have more fabric cells to enable more control and speed. Rectangular ones on the
other hand are used for recreation. These are safer and are more frequently used in
training programs for students
.
The force making the parachute fall
is gravity. Gravity is what holds
everything on the Earth and keeps the
Earth in its place in the Solar System.
Gravity forces the parachute down
but air resistance pushing up on the flat
surface of the parachute causes it to fall
slower to the ground. The air is forced
to move around the surface.
Research Question
• How does _____________
effect ________________?
OR
• What is the affect of
_______ on ___________?
Research Question
How does the surface area of a
parachute effect the rate at which the
parachute falls to the ground?
What affect does the size of a
parachute have on how fast it falls to
the Earth?
Prediction
• List 3
ways the
experiment
might end
up.
1. The smaller surface area will
cause the parachute to fall at a
faster rate.
2. The larger surface area will
cause the parachute to fall at a
faster rate.
3. The surface area will not affect
the falling rate of the parachute.
1.The smaller parachute will
hit the ground faster.
2.The bigger parachute will
hit the ground faster.
3.The parachutes will all hit
the ground at the same
time.
Hypothesis
• The
hypothesis is a
statement
that predicts
what you
think will most
likely happen in
the experiment.
I believe the smaller the amount of
surface area the parachute canopy
has the greater the falling rate in
seconds.
I believe the smaller parachute will
hit the ground faster than the bigger
parachutes.
Manipulated Variable
• The one thing
(or object) you
will change in
the experiment
The surface area of
the parachute.
The size of the
parachute.
Responding Variable
• Identify what you
will measure to see
if it is effected
( in the experiment )
The falling rate of the
parachute in
seconds.
How long it takes the
parachute to fall to
the ground.
Set-Up Conditions
• List all the
things
(materials /
procedures )
that will
remain
constant to
ensure a fair
trial.
• Two pieces of string 12 in. long to attach to
the four corners
• Sticky dots to attach the string to each
corner
• One paper clip to hang from the middle of
both strings
• Measuring tape to drop the parachute from
the exact height each time.
• A second story balcony from which you
drop the parachute
• A stopwatch to time the drop
Materials
• A list of
items that
will be used.
Include size,
quantity, and
descriptions
such that
some one
else could
duplicate
your project.
•
•
•
•
•
•
•
String or twine
Paper clips
Sticky dots
Paper napkins
Measuring tape/ meter stick
Stopwatch
Science Journal for recording
Experiment Directions
• Step-by step list of
what you did (or
how each item will
be used) in your
material list and
the exact order it
was done.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Cut a paper napkin in half, and then cut another in quarters to have the
three different size parachutes.
Cut your twine into 6 12-inch pieces
Attach one piece of twine to the corner of one uncut, unfolded napkin with
a sticky dot. Attach the other end to the opposite corner. Do this again
with the two empty corners and another piece of string. Do this for each
size parachute.
Hang the paperclip in the middle of the two pieces of string where they
meet. Make sure the paperclip is securely attached.
Go to the second story and measure the exact height you will drop the
parachute from to the ground. Have a parent or partner stand on the
ground directly below you with the stopwatch.
Hold the parachute by the middle of the canopy, line up the exact drop
point, and release the parachute.
As you release the parachute have a parent or partner start the timer
when you say start.
The parent or partner can then stop the stopwatch as soon as any part of
the parachute hits the ground.
Record the time in your journal.
Repeat this trial 11 times with each size parachute.
Data Collection
• An organized and
complete account
of everything that
was measured and
observed in the
experiment (using
metric units).
There should at
least 10 or more
trials.
Trial
#1
Trial
#2
Trial
#3
Trial
#4
Trial
#5
Trial
#6
Trial
#7
Trial
#8
Trial
#9
Trial
#10
Trial
#11
Mean
¼ Napkin
9.7
11.2
9.3
10.5
9.5
10.7
11.1
10.3
10.0
9.7
10.1
10.19
½ Napkin
28.7
26.5
27.1
27.5
26.0
26.8
26.1
26.2
27.3
27.5
26.2
26.9
1 Full
Napkin
50.5
51.0
48.5
49.1
49.5
48.7
48.8
50.0
49.0
48.9
48.6
49.33
Parachute
size
Trials
measured in
seconds
More on Data Collection…
• Data is usually
presented in a
chart form.
• Chart should
include
averages
(mean) of the
trials given.
Graph
• A mathematical
picture of the
data, using
(mean)
averages to
plot the data in
the experiment.
Falling Rate of Parachutes in
Seconds
Experiment Results
• Use the data and graphs (from
the experiment) to explain
what happened in the
experiment.
• Did your manipulated variable
affect your responding
variable? (if so explain how)
During this experiment with each drop of the
parachute the results were the same: the less
surface area the parachute had, the smaller the
amount of drag or wind resistance, and the faster the
parachute fell to the ground. The small parachute
fell to the ground at an average rate of 10.19
seconds, the mid-sized parachute fell at an average
rate of 26.9 seconds, and the largest parachute fell
at an average rate of 49.33 seconds.
My manipulated variable, the surface area of the
parachute, did effect my responding variable, the
amount of time it took the parachute to hit the
ground.
Every time we dropped the parachute the
same thing happened: the smaller the
parachute, the faster the parachute fell to the
ground. The small parachute fell to the
ground at an average rate of 10 seconds, the
mid-sized parachute fell at an average of 27
seconds, and the largest parachute fell at an
average of 49 seconds.
My manipulated variable, the size of the
canopy, did effect the amount of time (my
responding variable) it took the parachute to
hit the ground.
Experiment Conclusion
• Explain whether
or not you data
supports, or
fails to support
your
hypothesis.
(gives fact /
reasons from
your
experiment)
The data I collected during this experiment
proves my hypothesis that the more surface area
the parachute has the more air resistance it will
have and the parachute will fall to the ground
slower. Therefore, the smaller the parachute
canopy the faster a person would fall to the
ground.
The larger canopy consistently took longer to
hit the ground then the mid-sized or the smallest
canopies. The smallest canopy took the shortest
amount of time to hit the ground in every trial.
My hypothesis was that the
smaller parachute will hit the
ground faster than the bigger
parachutes.
My experiment proved that
my hypothesis was right. The
smaller parachute always hit the
ground first and faster than the
other two sizes of parachutes.
Experimental Real World
Uses
• A description of
ways, places,
or situations
where the
information
from your
experiment
might be useful.
Parachutes are used in real world situations all of the time. They
are used in times of war to airlift troops, they are used in times of famine
to feed starving populations, and they are used for recreation.
In times of war parachutes are a quiet and covert way for troops to
land behind enemy lines. We have been using paratroopers since WWI
in this country. These parachutes are often small to enable soldiers to
maneuver more easily.
In times of famine we use parachutes to drop food in places that
are inaccessible by truck or plane. These parachutes have to be very
large to accommodate the heavy boxes full of food and supplies in
drought stricken areas and to ensure things are not damaged!
Finally many people consider the use of parachutes in skydiving a
fun and dangerous sport for recreation. These parachutes are
lightweight and relatively small. I also found research to support the use
of a suit with an even smaller surface area like that of a flying squirrel.
This allows a lot of freedom o the skydiver and allows for incredible
speed. They are attempting to land without another parachute to
cushion the fall!
Parachutes are used in the real world.
There are three places they are used.
First they are used by soldiers. They
jump out of planes to land behind enemy
lines.
Second, they are used by the
government. The government uses them to
drop food for starving people in places cars
and trucks cannot go.
Finally they are used by skydivers. These
are people that jump out of planes for fun.
Anyone can go skydiving and watch the
parachute work!
Experimental Reflections
• A paragraph which
includes thoughts,
concerns,
discoveries, or further
questions to explore.
• What might you do
differently next time?
(give reasons)
While attempting this experiment I discovered
that a different material might be a better choice next
time. Paper napkins have a tendency to tear easily
and then another parachute must be made possibly
affecting the integrity of the experiment.
I also considered changing the experiment next
time to discover how the material effects the falling
rate of the parachute. I would also consider adding
more sizes for experimentation experiences.
Overall I was happy with the experiment and my
results. I can definitely expand on this experiment
next time I attempt it.
Science Content
Statement
Research Question
Data
Collection
Prediction
Responding
Variable
Set Up
Conditions
Graphs
Hypothesis
Manipulated
Variable
Directions
Materials
Diary
Results
Statement
Conclusion
Statement
Real World
Uses