# Waves, Sound and Light: Light Waves

## Light Waves: Audio Guided Solution

#### Problem 11:

The diagram at the right represents the interference pattern created by two water waves. The waves were created by two objects bobbing up and down in phase at the same frequency. Point P on the pattern is a distance of 36.9 cm from S1 and 61.5 cm from S2. Determine the wavelength (in cm) of the water waves.

## 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 = 3.00x108 m/s, λ = 554 nm, 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.