When a trumpet plays the note B-flat (f = 233 Hz) it produces a sound intensity

Question

When a trumpet plays the note B-flat (f = 233 Hz) it produces a sound intensity of 10^(-7) W/m^2 at a distance of 3.0 m from the instrument
(a) Assuming the trumpet radiates sound equally in all directions (not a very good assumption for a trumpet, but we'll try it anyway), what is teh total acoustic power produced by the trumpet?
(b) what is the sound intensity level in dB (decibel) at this location?

Choose one word from each pairing.
(c) If the intensity changes from 10^(-7) W/m^2 to 10^(-6) W/m^2, the (loudness/pitch) of the sound will (increase/decrease)
(d)If teh frequency (f) changes from 233 Hz to 262 Hz, the (loudness/pitch) of the sound will (increase/decrease)

USEFUL EQUATIONS:
I= P/(4*pi*r^2)
B (bels) = 10log(10) * I/Ii
Ii = 10^(-12) W/m^2

Explanation / Answer

a)

Total acoustic power

P=I*(4pi*r2)=10-7*4pi*32

P=1.13*10-5 Watts

b)

B=10Log(I/Io)=10log(10-7/10-12)

B=50 dB

c)

Loudness ,Increases

d)

Pitch

Related Questions

Navigate

• Browse (All)
• Browse W
• Subjects

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