Number of Rubber Bands vs Drop Distance

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Barbie™ Bungee Jumping
Name : __________________________________ Date : _________ Period : ___
Barbie™ Bungee Jumping
Graphing and Extrapolating Data
while investigating forces
Team members have been hired to work for the Evil Knievel Entertainment Company. This company provides
rock climbing, sky diving, “extreme skateboarding”, and hang gliding adventures to the public. The current
market research indicates that the company should add bungee jumping to its list of entertainment services. As
part of the preliminary research, the management has assigned teams the task of working out the details of the
jump to ensure a safe, yet thrilling experience. The company has several sites planned for bungee jumping and
each site is at a different height.
PURPOSE
To ensure a safe and thrilling jump, you will determine the relationship between the jump height and the
number of rubber bands used to make the bungee cord. You must allow your action figure to come as close to
the floor as possible without sustaining any injuries or fatalities.
MATERIALS
meter stick
rubber bands (7 to start)
balance
1 Barbie doll
PROCEDURE
1. Use one rubber band to secure Barbie’s™ ankles together and to serve as a point of attachment for the
bungee cord.
2. Mass Barbie™ on the balance. Record the mass in Data Table 1 in both grams and kilograms.
3. Construct a bungee cord composed of 2 rubber bands and attach it to Barbie’s™ ankles. Barbie will fall
from a standing position, plunging head first throughout this activity. Measure the initial length ( in
meters!) of the 2-band bungee cord you constructed once it is attached to Barbie’s™ ankles.
4. For the first few measurements, place the meter stick upright and hold Barbie™ as if she is standing on
top of it. This will be her initial launch platform. Test drop Barbie™ several times to practice taking
readings. Repeat this jump two more times and record the data (again in meters!!).
5. Add a rubber band to your attached bungee cord. Measure the new cord length. Drop Barbie™ three
times and record the data.
6. Repeat step 5 until you have a total of 6 rubber bands in your bungee cord. Record the data each time.
7. Average your data and then graph each point on the graph labeled “Number of rubber bands vs drop
distance”
8. Draw a “best fit” line on your graph. Remember that a best fit line will not necessarily go through all of
the points. You are not connecting the dots!! However, you will have a line that gets as close as
possible to the majority of the points. It should have equal numbers of points above the line as below the
line.
9. Use this line to extrapolate (predict based on information) how many rubber bands will be required to
drop Barbie™ safely from the distance your instructor gives you.
Distance = ____________________
Results = lived / died
/ maimed
# of rubber bands needed _________
Barbie™ Bungee Jumping
Name : __________________________________ Date : _________ Period : ___
Barbie™ Bungee Jumping
Graphing and Extrapolating Data
while investigating forces
DATA AND OBSERVATIONS________________________________________________
Data Table
Mass of Barbie™ = ____________ g
Number of
Rubber bands
=
_______________ kg
Initial Length
of Bungee (m)
Maximum Drop Distance
Trial 1
Trial 2
Trial 3
Average
Barbie™ Bungee Jumping
Name : __________________________________ Date : _________ Period : ___
Number of Rubber Bands vs Drop Distance
Conclusion questions__________________________________________________
1. The slope of a line can be calculated by taking two points on the line and using the
equation
Y2 - Y1
slope = -----------------X2 - X1
Find the slope of your line.
Barbie’s™ height is approximately 0.10 m.
This means that the equation of your line is y = mx + b where y= your drop distance in
meters, m= your slope, x= the number of rubber bands, and b winds up being Barbie’s height
of 0.10 m.
Write the equation for your line in the space below.
y = ___ x + 0.30
Barbie™ Bungee Jumping
Name : __________________________________ Date : _________ Period : ___
2. Using the equation of your best fit line from question #1, calculate how many rubber bands would be
required to allow Barbie™ a successful, yet thrilling jump from a height of 30 m (~100 ft). (Hint: put the 30
in place of the y and solve for x.)
3. Calculate the stretch coefficient for the trial using 4 rubber bands by using the following formula:
Stretch factor
=
Stretch factor
=
amount of stretch (Average drop distance – initial length of bungee)
-----------------------------------------------------------------------mass of Barbie™
4. List all of the forces that affected Barbie™ from beginning to end of her jump.
5. Calculate Barbie’s™ weight using the formula Wt = m · g
[weight = mass · acceleration due to gravity (9.8 m/s2) ]
Remember to convert Barbie’s™ mass from grams to kilograms (mass in grams ⁄ 1000)
Barbie’s™ weight = _____________ N
6. Ken wants to jump and have some fun too. Barbie™ offers to loan Ken her bungee cord, but warns him
that it may not be a safe idea. Why would it be a bad idea for Ken to use Barbie’s™ bungee cord? (Think
differences)
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