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Question
In 1866, the U. S. Congress defined the U. S. yard as exactly 3600/3937 international meter. This was done primarily because:A) length can be measured more accurately in meters than in yards
B) the meter is more stable than the yard
C) this definition relates the common U. S. length units to a more widely used system
D) there are more wavelengths in a yard than in a meter
E) the members of this Congress were exceptionally intelligent
Answer
This answer is hidden. It contains 1 characters.
Related questions
Q:
The intensity of the microwave background radiation, a remnant of the big bang:
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B) is least in directions toward the center of the galaxy
C) is proportional to the reciprocal of the distance from us
D) is proportional to the square of the distance from us
E) is nearly the same in all directions
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A) 105y
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Q:
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D) one quark and one antiquark
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Q:
Any meson is a combination of:
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C) one quark and two antiquarks
D) one quark and one antiquark
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Q:
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Q:
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Q:
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Q:
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Q:
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A) a proton
B) an omega minus
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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
C) the energy of the most energetic electron before it is ejected
D) the energy of the most energetic electron after it is ejected
E) the electron potential energy at the surface of the sample
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:
A) 0.18mc2
B) 0.22mc2
C) 0.25mc2
D) mc2
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Q:
A particle with zero mass and energy Ecarries momentum:
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Q:
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Q:
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An event occurs at x= 500 m, t= 0.90 in one frame of reference. Another frame is moving at 0.90cin the positive xdirection. The origins coincide at t= 0 and clocks in the second frame are zeroed when the origins coincide. The coordinate and time of the event in the second frame is:
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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:
Pi mesons at rest have a half-life of T.If a beam of pi mesons is traveling at a speed of, the distance in which the intensity of the beam is halved is:
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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C) G sent his signal before E but was the same distance away
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Q:
Figure (i) shows a double-slit pattern obtained using monochromatic light. Consider the following five possible changes in conditions:
1) decrease the frequency
2) increase the frequency
3) increase the width of each slit
4) increase the separation between the slits
5) decrease the separation between the slits
Which of the above would change Figure (i) into Figure (ii)? A) 3 only
B) 5 only
C) 1 and 3 only
D) 1 and 5 only
E) 2 and 4 only
Q:
The resolving power of a telescope can be increased by:
A) increasing the objective focal length and decreasing the eyepiece focal length
B) increasing the lens diameters
C) decreasing the lens diameters
D) inserting a correction lens between objective and eyepiece
E) none of the above
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?
A) 2.4 x 10-4
B) 1.7 x 10-3
C) 1.1 x 10-2
D) 1.0 x 10-1
E) 1.0
Q:
A plane wave with a wavelength of 500 nm is incident normally on a single slit with a width of 5.0 x10-6m. Consider waves that reach a point on a far-away screen such that rays from the slit make an angle of 1.0ï‚°with the normal. The difference in phase for waves from the top and bottom of the slit is:A) 0 radB) 0.55 radC) 1.1 radD) 1.6 radE) 2.2 rad