One Piano Is at Rest,and Another One Approaches at 3

question 58

Multiple Choice

One piano is at rest,and another one approaches at 3.4 m/s.Both pianists are playing middle C (512 Hz) .What beats does the pianist at rest hear as a result of the Doppler shift? (Use 340 m/s for v_sound.)

• A)10
• B)20
• C)5
• D)512
• E)no beats

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Definitions:

Ability-To-Pay Principle

The idea that those who have greater income (or wealth) should pay a greater proportion of it as taxes than those who have less income (or wealth).

Marginal Cost

the additional cost incurred to produce one more unit of a good or service.

Marginal Benefit

The added joy or utility one achieves by consuming an additional unit of a product or service.

Cost-Benefit Analysis

is a systematic approach to estimating the strengths and weaknesses of alternatives, used to determine the best option through weighing the cost against benefits.