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toothpaste666
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Homework Statement
A radio telescope, whose two antennas are separated by 55 m, is designed to receive 3.0-MHz radio waves produced by astronomical objects. The received radio waves create 3.0-MHz electronic signals in the telescope's left and right antennas. These signals then travel by equal-length cables to a centrally located amplifier, where they are added together. The telescope can be "pointed" to a certain region of the sky by adding the instantaneous signal from the right antenna to a "time-delayed" signal received by the left antenna a time Δt ago. (This time delay of the left signal can be easily accomplished with the proper electronic circuit.)
If a radio astronomer wishes to "view" radio signals arriving from an object oriented at a 12 ∘ angle to the vertical as in the figure (Figure 1) , what time delay Δt is necessary?
Homework Equations
dx/l = m(lambda)
The Attempt at a Solution
i use dx/l = dsin(theta)
x = lsin(theta)
they give me l = 55 m theta = 12 degrees
x = 55sin(12) = 11.4 m
which is the distance ahead that one sound wave is of the other
sound travels 343 m/s so it travels that distance in
1 s/ 343m (11.4 m) = .033 seconds
so that is how much they need to delay the signal.
is this valid?
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