# Waves, Sound and Light: Wave Basics

## Wave Basics: Audio Guided Solution

#### Problem 22:

Gillian drives down Lake Avenue and observes an odd vibrational pattern of her car antenna. She observes it vibrating back and forth in the manner shown at the right. There is an antinode at its free end and a node at the location where the antenna mounts to the car. Vibrations travel through the 86 cm tall antenna at 5.0 x 103 m/s. Determine the frequency of vibrations of the antenna.

## 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 = 12.8 m/s, λ = 4.52 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.