A radar receiver indicates that a pulse return as an echo in 20 s after it was sent. How far away is the reflecting object? (c = 3.0 108 m/s)
A) 1.5 km
B) 3.0 km
C) 6.0 km
D) 9.0 km
Question 2
Consider two pipes of the same length: one pipe is open at both ends and the other pipe is closed on one end but open at the other end.
If the fundamental frequency of the totally open pipe is 300 Hz, what is the fundamental frequency of the other pipe? A) 150 Hz
B) 300 Hz
C) 450 Hz
D) 600 Hz