Part One:

Question

The decibel level of the noise from a jet aircraft
is 130 dB when measured 19.3 m from
the aircraft.
How much sound power does the jet aircraft
emit?
Answer in units of W - 46673.5W

I need help with Part Two:
Part Two:
How much sound power would strike the
eardrum of an airport worker 19.3 m from
the aircraft? (Assume the diameter of the
worker’s eardrum is 1.7 × 10−2m)

Answer 1

the power is evenly distributed over the surface of a sphere with a radius of 19.3 m

46673.5 W / (4 π 19.3^2) m^2

calculate watts/m^2

calculate the area of the eardrum

FYI ... be aware of significant figures

Answer 2

It says this is incorrect

Answer 3

what is incorrect?

Answer 4

When I plug in the answers to that equation and do the work the quest says thats incorrect

Answer 5

have you learned about significant figures

did you notice the FYI

Answer 6

yes, the quest does not care about significant figures

Answer 7

see my response above. I have an issue with the sphere on a Jet)

Answer 8

130 dB is equivalent to 10 w/m^2

the area of the eardrum is ... π r^2 = π (8.5E-3)^2 m^2 = 2.27E-4 m^2

10 w/m^2 * 2.27E-4 m^2 = 2.27E-3 W = 2.27 mW (milliwatts)