An Enclosed Chamber with Sound Absorbing Walls Has a 2

question 42

Multiple Choice

An enclosed chamber with sound absorbing walls has a 2.0 m × 1.0 m opening for an outside window. A loudspeaker is located outdoors, 84 m away and facing the window. The intensity level of the sound entering the window space from the loudspeaker is 56 dB. Assume the acoustic output of the loudspeaker is uniform in all directions and that acoustic energy incident upon the ground is completely absorbed and therefore is not reflected into the window. The threshold of hearing is 1.0 × 10^-12 W/m². The acoustic power output of the loudspeaker is closest to

• A) 0.035 W.
• B) 0.070 W.
• C) 0.18 W.
• D) 0.35 W.
• E) 0.70 W.

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Definitions:

NPV

Net Present Value, a method used in capital budgeting to evaluate the profitability of an investment by calculating the present value of expected cash flows minus the initial cost.

Discount Rate

The interest rate used in discounted cash flow analysis to determine the present value of future cash flows.

Capital Rationing

The practice of limiting investments or expenditures in new projects due to budget constraints or capital availability.

IRR

IRR (Internal Rate of Return) is a financial metric used to evaluate the profitability of an investment, representing the interest rate at which the net present value of cash flows from the investment is zero.