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Question
A man pulls a 100-N crate up a frictionless 30°slope 5 m high as shown. Assuming that the crate moves at constant speed, the work done by the man is:
A) -500 J
B) -250 J
C) 0 J
D) 250 J
E) 500 J
Answer
This answer is hidden. It contains 1 characters.
Related questions
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The intensity of the microwave background radiation, a remnant of the big bang:
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Q:
Any meson is a combination of:
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Q:
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Q:
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Q:
In a photoelectric effect experiment at a frequency above cut off, the stopping potential is proportional to:
A) the energy of the least energetic electron before it is ejected
B) the energy of the least energetic electron after it is ejected
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D) the energy of the most energetic electron after it is ejected
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Q:
In a photoelectric effect experiment at a frequency above cut off, the number of electrons ejected is proportional to:
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Q:
The units of the Planck constant hare those of:
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Q:
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Q:
A particle with rest mass m moves with speed 0.6c. Its kinetic energy is:
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A particle with zero mass and energy Ecarries momentum:
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Q:
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Q:
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Q:
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Q:
A meter stick moves sideways (that is, in a direction perpendicular to its length) at 0.95c. According to measurements taken in the laboratory, its length is:
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Q:
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Q:
A train traveling very fast (v= 0.6c) has an engineer (E) at the front, a guard (G) at the rear and an observer (S') exactly half way between them. Both E and G are equipped with yellow signaling lamps. The train passes a station, closely observed by the station master (S). Both E and G use their lamps to send signals. According to both S and S' these signals arrive simultaneously at the instant S' is passing S. According to S':
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Q:
Figure (i) shows a double-slit pattern obtained using monochromatic light. Consider the following five possible changes in conditions:
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2) increase the frequency
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4) increase the separation between the slits
5) decrease the separation between the slits
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Q:
The resolving power of a telescope can be increased by:
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Q:
Light of wavelength 480 nm falls on a slit of width 3.5 m. What is the relative intensity (that is, the value of I/Im) of the diffraction pattern at an angle of 18?
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Q:
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