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This is a Practice Exam from Summer 2006
SHOW YOUR WORK,
Document your reasoning, showing algebra,
conversion factors and diagrams.
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9-B35 (Sister) Your
great-great granddaughter takes a grandfather clock to her
vacation home on Earth’s Moon where the acceleration due to
gravity is about 1/6 as great as here at home. Here on
Earth, where the acceleration due to gravity is 9.81 m/s2
the period of the pendulum is 2.000 s. (a) What is the
effective length of the pendulum? (0.994 m )(b) What would
be the period of that pendulum on the Moon? ( 4.90 s ) |
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10-AI4
{Substantially revised with a part added)
Some young folks who don’t listen to loud music can hear
sound with a frequency as low as 15 Hz and as high as
22,000 Hz. If the speed of sound is 340 m/s, what is
the (a) shortest wavelength such a person can hear?
( 15.5 mm) What is the (b) longest wavelength such a
person can hear? ( 22.7 m) |
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10-BI3 (Little
revised) Our campus radio station KUXA is broadcasting on
a frequency of 88.300 MHz. (a) What is the wavelength of
the electromagnetic waves? (3.39516 m ) (b) If, as a joke,
rival football fans set up a pirate transmitter, simultaneously
broadcasting at 88.303 MHz, how many beats per second are
heard? ( 3 kHz) The speed of light is 2.99793 x 108
m/s. ( )
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11-B22 (Modified
to fit an actual classroom demonstration.) One UArk
cheerleader and one physics professor can produce twice as much
sound energy as the professor by himself when Calling The
Hoggs, but not nearly as much as the whole class.
Given: Alone each can produce a sound level
intensity of 87 dB relative to the threshold of hearing
of 10-12 W/m2. The whole class can
generate 16 times the energy level of either alone.
Find: (a) What is the energy level of a UArk
cheerleader? ( 5 x 10-4 w/m2 )
(b) What is the sound
level intensity of the two together? ( 90 dB )
(c) What is the sound
level intensity of the whole class? (99 dB )
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12-B7 The
density of blood is about 1.1 g/cm3. If there
were no structures in a giraffe's neck to give partial support
to the blood, what would be the difference in pressure, in torr,
between the blood in a giraffe's brain and that in its heart?
The brain is 2.2 m above the heart. ( 1 torr = 1 mm of
Hg, and the density of Hg is 13.6 times that of water.) (
178 torr)
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12-B12 (sister)
A rock hound finds a shiny heavy golden rock. Wondering
if he has struck gold, he weighs it in air and then under water.
Given: Weighed in air, he finds it is balanced by
2.21 kg. Weighed under water the rock is balanced by
1.89 kg. Gold is 19.6 times as dense as water.
Find: (a) What is the density of the rock? ( 6.91
kg/L)
(b)
What would be the apparent mass of the rock under water if it
were real gold? ( 2.10 kg ) |
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