Transcript Daniel Bernoulli

Daniel Bernoulli
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December 15, 2005
Daniel Bernoulli
• He was born in
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Groningen, Netherlands
on Feb 8, 1700
He died on March 17,
1782 in Basel,
Switzerland
Went to college at Basel
University at the age of
13 to study philosophy
and logic
Daniel Bernoulli
• He was one of the many mathematicians that evolved
from his greedy, jealous family
• When Daniel’s book was published his father was the
one that was trying to take the credit for the book, this
went on until his father’s death
Daniel Bernoulli’s Major
Accomplishments
• His most important work was a book that was
published in 1738 called Hydrodynamica
• Hydrodynamics was a term he invented
• His book contained for the first time the
correct analysis of water flowing from a hole
in a container
Daniel Bernoulli’s Major
Accomplishments
• Another one of his major accomplishments is
Bernoulli’s Principle
•He won the Grand Prize of the Paris Academy
10 times, for topics in astronomy and nautical
topics
•Another important aspect of his work that
proved important in the development of
mathematical physics was his acceptance of
many of Newton's theories
Daniel Bernoulli Studies
Bernoulli’s Principle
• As the velocity of a fluid increases, the pressure
exerted by that fluid decreases
• Bernoulli’s principle is used for many things in the
world, including sports
Bernoulli's Equation
The Bernoulli equation states that,
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Where:
points 1 and 2 lie on a streamline,
the fluid has constant density,
the flow is steady, and
there is no friction.
Bernoulli’s Explanation of a Curve
Ball
• A spinning baseball has more • The stitches on a ball
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air turbulence on top of the
ball, producing slower air
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speed over the ball
air moving under the ball
accelerates and moves faster,
producing less pressure on the
bottom of the ball
This occurs partly because of
the relationship between the
pressure of a fluid and its
velocity
actually make it curve
The pitcher's fingers hold
the ball along a seam so
when the ball is thrown
with a snapping motion it
has topspin
Picture of how The Curve Ball
Works
Uses of Bernoulli’s Principal
• Baseball is not the only sport that illustrates physics
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phenomena
Football, soccer, bobsledding, hockey and others
involve the use of energy, work, friction, and inertia
Airplanes get a part of their lift from the use of
Bernoulli's principle
Race cars use Bernoulli's principle to keep their rear
wheels on the ground while moving at high speeds.
Bernoulli’s Research
• Bernoulli's research resulted in the first effective
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method of measuring blood pressure
Fluid's pressure is determined by its velocity, the
pressure decreasing as the velocity increase
Bernoulli's research related pressure to the law of
conservation of energy
His research placed the behavior of fluids squarely
within the realm of mathematical and mechanical
physics
Environment In Which Bernoulli Did
Research
• Daniel Bernoulli did most of his research
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in Basel, Switzerland
He did some of his work with Leonhard
Euler who he lived with in Russia
He also worked at St Petersburg
Academy of Sciences with Leonhard
Euler
Hypothesis
• The hypothesis is if Daniel Bernoulli
never came up with his research then
people would not be able to check there
blood pressure, sports wouldn’t be what
they are if he did not figure out the
principle.
ACTIVITY 1: BE RNOULLI'S
PRINCIPLE
MATERIALS
• 2 tennis or ping-pong balls
• string
• masking tape
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PROCEDURE
Attach one end of a string to a tennis or ping-pong ball with the masking
tape.
Do the same to the other string and ball.
Hang the balls from a horizontal bar or a dowel rod. Place the balls at the
same level and about 3 cm apart.
Put your mouth between the two balls about two or three inches from them.
What do you think will happen to the balls when you blow a steady stream
of air between them?
What did you observe?
Activity 2: Fastball Egg Toss
Materials
• raw eggs
• old bed sheets
Procedure
• Hold a flat bed sheet at each of the four corners to provide a
large target for the pitcher. Make a pocket in the bottom of the
sheet by holding it up slightly
• Throw an egg into the sheet as fast and hard as you can. The
object is to break the egg by throwing it into the sheet
• An egg cannot be thrown hard enough into a sheet to break the
shell because the sheet, which transfers the momentum of the
egg over a long period of time, greatly decreasing the force on
the egg shell
• Compare what happens when momentum is transferred
abruptly. Drop the raw egg on a solid surface. Now time is
very short, making the force much greater
References
• http://www.pbs.org/safarchive/4_class/45_pguid
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es/pguide_405/4545_bb.html
http://www.infoplease.com/ce6/sci/A0807244.ht
ml
http://www.stetson.edu/~efriedma/periodictable
/html/B.html
http://hyperphysics.phyastr.gsu.edu/hbase/pber.html
http://www.du.edu/~jcalvert/tech/fluids/bernoul
.htm