Question Detail

PHY 104 Pitch, loudness, quality, timber Objective Question
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Question

If the intensity at point B (r=3m) is IB, what is the intensity at point C (r=9m) in terms of IB, based on the inverse-square law?
Options
A I<sub>C</sub> = 3 * I<sub>B</sub>
B I<sub>C</sub> = (1/3) * I<sub>B</sub>
C I<sub>C</sub> = (1/9) * I<sub>B</sub>
Correct Answer
D I<sub>C</sub> = (1/81) * I<sub>B</sub>
Correct Answer

Option C is the correct answer.

Detailed Explanation

According to the inverse-square law, I ∝ 1/r². So, IB * rB² = IC * rC². We have IB * 3² = IC * 9². This means 9 * IB = 81 * IC. Therefore, IC = (9/81) * IB = (1/9) * IB.

Hint

The intensity is inversely proportional to the square of the distance. If the distance triples, how much does the intensity change?

Question Info

Course: PHY 104
Topic: Pitch, loudness, quality, timber
Type: Objective
Difficulty: Not specified
Question 474 of 947
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