# Waves, Sound and Light: Sound and Music

## Sound and Music: Audio Guided Solutions

#### Problem 20:

Two strings made of the same material (same mass density) and stretched to the same tension (and thus, having the same speed) have a different length. One of the strings is 80-cm long (String A) and the other string is 60 cm (String B). They are vibrated at various frequencies in order to establish standing wave patterns within them. Consider the first six harmonics of the two strings. Which harmonic of String A would have the same frequency as one of the harmonics of String B?

## Audio Guided Solution

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## Habits of an Effective Problem Solver

• Read the problem carefully and develop a mental picture of the physical situation. If necessary, sketch a simple diagram of the physical situation to help you visualize it.
• Identify the known and unknown quantities and record in an organized manner, often times they can be recorded on the diagram itself. Equate given values to the symbols used to represent the corresponding quantity (e.g., v = 345 m/s, λ = 1.28 m, f = ???).
• Use physics formulas and conceptual reasoning to plot a strategy for solving for the unknown quantity.
• Identify the appropriate formula(s) to use.
• Perform substitutions and algebraic manipulations in order to solve for the unknown quantity.