Name:_____________________________________Date:___________________Period:_____________
Breaking Force of Hair Lab
Hypothesis:
Today we will be doing an experiment to test the strength of human hair! How strong do you think a
tiny strand of your own hair can be? Let’s find out!
State your hypothesis: How many pennies do you think one strand of human hair can hold?
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Materials:
-Stack of books
-Pencil
-Tape
-Pennies
-Scissors
-Strand of hair (x3)
Procedure:
1.
2.
3.
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5.
Use the electronic scale to measure the mass of one penny.
Obtain a stack of books for your experiment.
Obtain 3 different strands of hair and cut to the same size of 15 cm.
Securely tape on end of your first strand of hair onto the pencil.
Wedge the pencil into the stack of books so that the pencil is sticking out and the hair is
hanging down.
6. Securely tape one penny onto the strand of hair and see if the hair can hold it.
7. Keep taping on pennies until the strand breaks.
8. Repeat with each sample strand of hair (x3).
Data Collection:
Trial 1
Trial 2
Hair Strand Type
Mass of penny
# of pennies to break hair
Total weight of pennies + hair
Results:
Find the total force required to break the strand of hair for each trial.
Trial 3
Name:_____________________________________Date:___________________Period:_____________
Calculations: Force = mass x acceleration
Calculate the total force required to break the strand of hair for each trial. Use the total weight of
pennies + tape and multiply by the acceleration of gravity (9.8 m/s2).
Trial 1 total force: __________ Newtons
Trial 2 total force: __________ Newtons
Trial 3 total force: __________ Newtons
Average total force: __________ Newtons
Conclusions:
Was your hypothesis correct or incorrect? Why?
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What was your reaction to your results? Were you surprised by the strength of human hair?
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What other factors could have impacted your results? Think about different hair types, materials used,
etc.
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There are lots of other experiments you could try with this. What are other ways you could test hair
strength? Think about wet hair vs. dry hair, multiple strands, different hair types (curly and straight),
etc.
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