1 A. You leave the main stage and wander over to one of the tents, hoping for a

Question

1 A. You leave the main stage and wander over to one of the tents, hoping for a better experience. Inside the tent, you notice some thumping bass, but realize it sounds different from what you are used to. The artist has placed the subwoofer on a train that circles around the perimeter of the tent. You hear the sound coming from the subwoofer on the train and also the sound reflecting off the far side of the tent, creating a 1.5 Hz beat frequency. If the subwoofer is emitting at 43 Hz, how fast is the subwoofer on the train moving toward you?

B.Below is a snapshot graph at t= 0 s of a wave pulse approaching the end of the rope from the right at 1.5 m/s (moving towards x= 0 m). The rope is tied to the wall at x= 0 m. Draw two snapshot graphs stacked vertically, showing the string at t=3 and 4 s.

Showing how you got the answers would be great. Thanks

Explanation / Answer

Let Speed of Sound = 344 m/s
f/ = f (v +/- vO) / (v -/+ vs )

The Reflected Wave has Frequency,
f/ = f (v ) / (v - vs )
f' = 43 * 344 / (344 - vs)

This is the Second Frequency heard by the Observer.

Beat Frequency, fb = f' - 43
1.5 =  f' - 43
f' = 43 + 1.5
f' = 44.5 Hz
43 * 344 / (344 - vs) = 44.5

Solving for vs
vs = 11.6 m/s
Speed of subwoofer on the train moving toward you, vs = 11.6 m/s

Please post seperate question in seperate post.

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.