7. (a) What is meant by the frequency of a wave? Give the relationship between the frequency and the wavelength of a wave - Leaving Cert Physics - Question 7 - 2013

The relationship between frequency (f), wavelength (λ), and the speed of light (v) can be expressed by the formula:

$v = f \cdot \lambda$

From this, we can derive that frequency is inversely proportional to the wavelength:

$f \propto \frac{1}{\lambda}$

As the student moves from point A to point B, he will notice that the loudness of the sound varies. Specifically, he will experience an increase in loudness when he is equidistant from both speakers, and a decrease when he is closer to one speaker compared to the other.

This phenomenon is known as interference.

Interference occurs when waves from the two loudspeakers meet. At certain points, the waves can reinforce each other (constructive interference) or cancel each other out (destructive interference).

Here’s a simple representation:

• When waves meet at points where the peaks align, they produce a louder sound.
• When a peak from one wave meets a trough from another, they cancel each other out, leading to reduced or no sound.

1. Fundamental Frequency: This is the lowest frequency produced by a vibrating object, such as a guitar string. It determines the main pitch of the note.

2. Overtones: These are higher frequencies that occur alongside the fundamental frequency, contributing to the timbre or quality of the sound.

3. Resonance: It is the amplification of sound caused by the matching of the frequency of the sound wave with the natural frequency of the body of the guitar.

The note can be changed by altering the tension of the string (tightening or loosening it), changing the length of the vibrating part of the string (using a fret), or adjusting the thickness of the string.

Resonance is the phenomenon that occurs when an object vibrates at its natural frequency in response to an external force. This amplifies the sound produced, leading to a richer, fuller tone.