The trick of the balancing fork is mentioned on many web sites. A good one is the one from Harvard University.
Explain the physics behind the balancing Forks in your own words.
Use the words torque, net torque, distance, and pivot in your explanation.
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Describe how a pendulum and a mass on a horizontal spring satisfy those conditions (ignore any friction forces); also, include another example of a system that undergoes simple harmonic motion and discuss how it satisfies the conditions mentioned above.
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Let's assume that there was some mechanism by which we could remain suspended in air. By this I mean that our feet is not in contact with the ground. One possible way of doing this would be by means of a jetpack. If we could remain suspended in air for a while in this manner, will we be in a different place when we come down, due to the Earth's rotation? When I thought of this problem in the micro scale using a ball (which rotates), it appears like I'll be in a different place when I come down from my suspended state. Am I overlooking something here?
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If one were to use a different battery, would the capacitance of a capacitor change?
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350 nm of light falls on a single slit of width 0.20 mm. What is the angular width of the central diffraction peak?
In a single slit diffraction experiment, if the width of the slit increases, what happens to the width of the central maximum on a screen?
In a double slit experiment, if the separation between the slits increases, what happens to the distance between the interference fringes?
Which of the following colors produces the widest diffraction pattern
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orange |
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green |
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violet |
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red |
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1. At what altitude above the Earth’s surface is the acceleration due
to gravity equal to g/6?
2. Derive the escape speed for an object launched from the earth.
3. Calculate the escape speed for an object launched from
a) the Earth.
b) the moon.
4. •• Show that the speed of a satellite in a circular orbit a height h above the surface of the Earth is
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(a) A constant force < 31, -13, 36 > N acts through a
displacement < 0.17, 0.34, -0.24 > m. How much work does this
force do?
Work =
?J
(b) An object with mass 7 kg moves from a location < 28, 28, -43
> m near the Earth's surface to location < -34, 16, 45 >
m. What is the change in the potential energy of the system
consisting of the object plus the Earth?
Change of potential energy = ?J
(c) A spring whose stiffness is 900 N/m has a relaxed length of
0.59. If the length of the spring changes from 0.48 m to 0.86 m,
what is the change in the potential energy of the spring?
Change of potential energy = ?J
(d) You observe someone pulling a block of mass 33 kg across a
low-friction surface. While they pull a distance of 6 m in the
direction of motion, the speed of the block changes from 3 m/s to 5
m/s. Calculate the magnitude of the force exerted by the person on
the block.
F = ?N
(e) What was the change in internal energy (chemical energy plus
thermal energy) of the person pulling the block?
Change in internal energy = ?J
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Magnetism
What types of poles are there and how do they interact?
Explain three situations in which a magnetic force will interact. (hint: two poles, current carrying wire, moving
charge)
What affects the induced current of a coil in a magnetic field?
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What is the most important characteristic of muscle architecture that dictates its maximal force production?
a.) Tendon length b.) Number of sarcomeres in series c). Anatomical cross-sectional area d). Physiological cross-sectional area
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You are camping in a tent, you have some very hot water (700C) in a water bladder, but you realize that in fact you do not have enough drinking water. Your plan is to melt the block of ice you have seen in front of your tent using the boiling water you have and then treat the entire quantity. You estimate that the ice block has about 1 kg and is at a temperature of about -200C. How much water do you need to melt the ice and rise its temperature to 50C?
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A transformer contains four times as many turns in the secondary coil as it does in the primary coil. If the input voltage is 4000 V, what is the output voltage?
1000 V
2000 V
4000 V
8000 V
16000 V
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A gymnast of mass 62.0kg hangs from a vertical rope attached to the ceiling. You can ignore the weight of the rope and assume that the rope does not stretch. Use the value 9.81m/s2 for the acceleration of gravity.
Calculate the tension T in the rope if the gymnast hangs motionless on the rope.
Calculate the tension T in the rope if the gymnast climbs the rope at a constant rate.
Calculate the tension T in the rope if the gymnast climbs up the rope with an upward acceleration of magnitude 1.20m/s2 .
Calculate the tension T in the rope if the gymnast slides down the rope with a downward acceleration of magnitude 1.20m/s2 .
*all answers in Newtons
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(a) In a proton at one certain moment, the down quark has a strong color charge of red. What are the color charges of the two up quarks? (Type each color in lowercase with a space between each one.)
(d) In a pi meson at a certain time one quark has a red color. What is the color of the antiquark at that time?
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Show that a satellite may speed down: that is, show that if frictional forces or reverse thrust cause a satellite to lose total energy, it will move into an orbit closer to the earth and may have increased kinetic energy.
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Q1
Calculate the period of a satellite orbiting the Moon, 100 km above the Moon's surface. Ignore effects of the Earth. The radius of the Moon is 1740 km.
Express your answer using two significant figures.
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