Transcript Carousel Physics - Chariho Regional School District

Carousel Physics
Physics H 1W
June 2007
Outline
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Conscious Commuting
Carousel History
Questions and Calculations
Horizontal Accelerometer
Summary Sheet
Reflection
Conscious Commuting
Force
on 20mph
me in
20mph
95lb . . kg
0.44m/s
= 42.27kg
= 8.8m/s
Convert
My
weight
2
2
Find
the
8.8m/s
–
0m/s
=
0.733m/s
20mph in 12
seconds
) = 414.25N
when
the bus 0 to(42.27kg)(9.8m/s
2.2lb
1 mph
to
Newtons:
m/s:
acceleration:
12s – 0s
begins to move:
(42.27kg)(0.733m/s2) = 30.99N
Conscious Commuting
When
the
bus
traveling
at
a constant
speed
When
If you
the
eyes
busis
are
starts
closed,
up do
how
you
can
feel
youthrown
tell
when
doforward
you bus
feel
as
ifaround
you are
moving?
the
or
goes
backward?
a corner?
You
do can
not
feel
like youto
are
moving
because
the
When
You
the tell
bus because
begins
you
accelerate
fall
to one
you
side
feel
or
bus
is traveling
at the
a
constant
thrown
the
other
backward
when
because
bus goes
thespeed,
bus
around
isthe
pulling
a bus
corner.
isn’t
accelerating or decelerating.
us forward.
What is a Carousel?
• It’s an amusement ride made of a rotating platform
with seats for the passengers
• The seats are typically horses, but can include dogs,
cats, rabbits, pigs, deer…
• Animals often move mechanically up and down to
simulate galloping
• Music is often looped while the ride spins
Origins of the word “Carousel”
• Originates from the Spanish word “carosella” which
means “little war”
• In the 1100’s Turkish and Arabian horsemen used
carousels as an exercise to prepare for combat and as
a game.
• It was used to train men in cavalry because it
prepared and strengthened the riders for combat.
“Flying Horses”
• Early carousels didn’t have platforms, just the animals
hanging from poles and chains
• The animals would fly out from the centripetal force
when the device began to spin
• The carousels were either pulled by walking animals,
people pulling ropes, or cranking
Platform
• The platform carousel was developed in the
mid 1800’s
• The animals were attached to the wooden
floor which was suspended in the air from a
centerpole
• Theses devices were steam-powered
1909 Illions Carousel
Speed
4 Revolutions/Minute
Diameter
7.75 Meters
Circumference of the
outer ring of the
horses
Angle banking of the
floor
50 Meters
-4°
Manufacturer
M.C. Illions
Direction of travel
Clockwise
Questions and Calculations
Where would you need to sit if you wanted to experience the greatest
speed?
You would want to sit on the outside because all the horses complete
the circle in the same amount of time. The horses on the outside
have to travel more distance in the same amount of time, which gives
them a faster linear speed. Linear velocity is different between the
two rows of horses while the angular velocity is the same between all
the horses.
If you were on a horse and were to drop a coin while the ride was in
motion, where would it land relative to you?
It would land behind you because of centripetal force.
Questions and Calculations
Find centripetal
acceleration:
aR = v2 = (3.33m/s)2 = 2.86m/s2
r
3.875m
Find the frequency
in Hertz:
4 rev . min = 0.0667Hz
min
60s
Find linear velocity 50m – 0m
15s – 0s
= 3.33m/s
Horizontal Accelerometer
Vertical Direction:
T = mg/cosØ
Turn onto 95: 15°
90° - 15° = 75°
Horizontal Direction:
T = mg/sinØ
mg tanØ = ma
a = g tanØ
a = (9.8m/s2)tan(75) = 36.57
Summary
Name the ride that fits the description
Kinetic energy is being converted into gravitational potential energy:
Scream, they carry you up to the top, which uses kinetic energy. When
you’re at the top you have gravitational potential energy. PEgrav = mgy
The translational (linear) accelerations is negative:
Mind Eraser, at the end of the ride you come to an abrupt stop.
v2 – v1 = a
t2 – t1
The centripetal acceleration is significant:
Nightwing, because the ride spins in a circle really fast to make you feel
like you are flying. aR = v2
r
Reflection
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Had a good time
Bus didn’t break down
Stay at the park later
Buy the flash passes
Lunch buffet