A SETI search using the 300-meter diameter Arecibo radio telescope can pick up a 10 million Watt at a distance of 1,000 light-years
If we were to detect a similar signal coming from 10,000 light-years away, how powerful would the alien antenna have to be? A) 1 billion Watts
B) 10 million Watts
C) 10 billion Watts
D) 100 million Watts
A
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To what do the terms node and antinode refer?
a) antinodes are points of no oscillation; nodes are points of maximum oscillation b) nodes are points of no oscillation; antinodes are points of maximum oscillation
Duff states that equal masses of all substances have equal changes in internal energy when they have equal changes in temperature. Javan states that the change in internal energy is equal to a constant times the change in temperature for every ?T, no matter how large or how small ?T is, but that the constant is different for different substances. Which one, if either, is correct?
A. Neither, because the specific heat depends on the substance and may vary with temperature. B. Neither, because a change of state may involve release or absorption of latent heat. C. Neither because a substance may do work during a temperature change. D. All of the statements above are correct. E. Only statements (a) and (b) are correct.
A pipe of length L closed at one end is resonating at its fundamental frequency. Which statement is correct?
A) The wavelength is 4L and there is a displacement node at the pipe's open end. B) The wavelength is 4L and there is a displacement antinode at the pipe's open end. C) The wavelength is L and there is a displacement node at the pipe's open end. D) The wavelength is L and there is a displacement antinode at the pipe's open end.
One similarity between electrons and photons is
A) both are the quanta of a field. B) both are particles of matter. C) Both of the above. D) both are forms of radiation. E) None of the above.