Parachute Lab by EO1GkU6

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									Physics                                   Parachute Lab                                    Fall 2010

Lab Groups: 4-people max

Abstract

How does a parachute work? Do bigger parachutes work better than smaller parachutes? Find
out in this experiment if the size of the parachute matters.

Objective

In this experiment you will test different sized parachutes to see how changes in the size of
the parachute affect flight.

Introduction

In the sport of skydiving, a person jumps out of an airplane from a
very high altitude, flies through the air, and releases a parachute to
help them fall safely to the ground. The parachute slows down the
skydiver's fall so that they can land on the ground at a safe speed.
How does the parachute do this?

As the skydiver is falling, the force of gravity is pulling them
towards the earth. The force of gravity can make an object fall very
fast! The parachute slows the skydiver down because it causes air
resistance, or drag. The air pushes the parachute back up, and
creates a force opposite to the force of gravity, slowing the skydiver
down. As the skydiver falls slowly to the earth, these "push and
pull" forces are nearly in balance. The drag force from the parachute
                                                                            As the skydiver falls, the
is slightly less than the force of gravity, so the skydiver floats slowly
                                                                            forces of gravity and drag
to the ground.                                                              are in balance
                                                                            (SEED, 2006b).
In this experiment, you will test whether the size of the parachute is
important for slowing down the speed of the fall. You will make a series of parachutes from
small to large and test how quickly they fall from the same height. Will the large parachutes
fall more slowly than the small parachutes?


Terms, Concepts and Questions to Start Background Research

To do this type of experiment you should know what the following terms mean. Have an adult
help you search the internet!

       parachute
       air resistance
       drag
       load
       gravity
       surface area
Physics                                      Parachute Lab                                    Fall 2010

Questions
        How does a parachute work?




        HYPOTHESIS 1: Do bigger parachutes work better than smaller parachutes?




Materials and Equipment

        Square paper napkins
        metric ruler
        scissors
        washers
        twist ties
        light weight string
        stopwatch
        scotch tape

Experimental Procedure

       1. Secure 4-washers with a plastic-tie. You will use this for all trials. Determine mass in
           Kg. _______________
       2. Complete the table below for the control. Drop the washers from a know height. This
           height will be used throughout all trials.

                            Height = ______________ m


                      Average time to reach ground from              Calculate “g” by using
            Trial
                      rest in seconds. At least 2-timers per trial   xf = xo + v0t + 1/2gt2

            1

            2

            3

            4

                Average “g” with STDev

                *******Honors Physics: Calculate Vf for each trial.
Physics                                 Parachute Lab                                  Fall 2010

     3. Each parachute will be made out of paper napkin material. Photograph each of your
         parachutes. Ask e-mail them to Mr. Bean to print-out




     4. You will make a series of parachutes of different sizes, from large to small. Each
         parachute will be square in shape, so the four sides will each be of the same length.
         A list of sizes to try are shown in the data table below:


                Parachute     Length of Each Side (cm)     Surface Area (cm2)

                1             20                           400

                2             30                           900

                3             40                           1600

                4             50                           2500

     5. Make four differently sized parachutes from the napkin material, 1-layer thick. Use
         scotch tape for bigger parachutes. Tie a knot in each of the four corners of your
         square. The knots will be used to anchor your string.




     6. Cut out four pieces of string for each parachute. Each piece of string should be 40 cm
         long.
     7. Tie one end of each piece of string around one of the four knots, positioning the string
         right above the knot.
     8. Hold the center of the napkin in one hand and pull all strings with the other to collect
         them. Tie the free end of the strings together with an overhand knot:




     9. *Attach 4 washers to the bundle of strings with a twist tie. Be sure that each
         parachute has the same number of washers attached, or this will alter your results!




     10. Bring a stopwatch and the parachutes to a safe, high surface for your tests, at least
         2 meters from the ground. A good place for your test might be a secure balcony
         (Senator Square), deck or playground platform.
Physics                                   Parachute Lab                                  Fall 2010

     11. Using your stopwatch, time how long it takes in seconds for each parachute to fall
         to the ground. If the parachute does not open during a trial, just do that trial over so
         that when you are finished you have three trials which all worked. Test each
         parachute three times, and make an average of your data. Calculate the average by
         adding together your three times, and then dividing your answer by three. You can
         also increase the number of trials above three to get better data and organize your
         data table accordingly. You should keep your data in a table, and here is an example
         for an experiment with three trials: (VIDEO your trials if possible)


                                                                      Average Time
               Parachute     Trial 1       Trial 2      Trial 3
                                                                      With STDev
               #             (seconds)     (seconds)    (seconds)
                                                                      (seconds)

               1

               2

               3

               4

     12. Now make a graph of your data using MS Excel. Make a line graph of time vs.
         surface area. "Time, in seconds," should be on the y axis, and "Surface area, in
         square cm," should be on the x-axis. After you connect the dots, your line may slope
         up or down. Print graphs, photos, and attach for the group.

     Conclusion: answer individually using complete sentences on a separate sheet of paper.

     What does this tell you about this relationship (objective)?

     How does it relate to your hypothesis?

     How does your groups results compare with other groups?

     Possible sources of error?

Credits

      This project was based on two projects from the NASA Explores Program and one from the SEED
          program at Schlumberger:
              o NASA, 2003a. "Just 'Chute Me," NASA Explores: National Aeronautics and Space
                   Administration (NASA). [accessed November 3, 2006]
                   http://nasaexplores.com/show_k4_teacher_st.php?id=030519160632
              o NASA, 2003b. "Parachute Area Versus Drop Time," NASA Explores: National Aeronautics
                   and Space Administration (NASA). [accessed November 3, 2006]
                   http://nasaexplores.com/show_58_student_st.php?id=030509111221
              o SEED, 2006a. "Make a Parachute,"Schlumberger Excellence in Educational Development
                   (SEED). [accessed November 3, 2006]
                   http://www.seed.slb.com/en/scictr/lab/parachute/index.htm

								
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