Lesson 1 Objective

At the end of this section, you should be able to:

• define the common characteristics of waves such as period, frequency,
  wavelength and amplitude;
• describe terms like crest, trough and wave speed;
• relate wave frequency, period, wavelength, and velocity;
• solve problems involving wave properties.

Brainstorming Question

Have you ever played a swing, guitar or kirar? Have you ever slapped water with your hands and observed what happened? Discuss such phenomena or motion.

key terms and concepts

Period, Frequency, Amplitude, Wave speed, and Wave length are common characteristics of all waves.

Common Characteristics of Waves

Waves share common characteristics such as period, frequency, amplitude, wave speed, and wavelength.

Figure 6.1 Characteristics of wave.

• Rest Position: The undisturbed position of particles when not vibrating.
• Displacement: The distance a point in the medium moves from its rest position.
• Trough: The lowest point below the rest position.
• Crest: The highest point above the rest position.
• Period (T): The time for one complete cycle of periodic motion.
• Frequency (f): The number of complete waves passing a point per unit time, measured in Hertz (Hz).
• Amplitude (A): The maximum displacement from equilibrium position, measured in meters (m).
• Wave Speed (v): The distance a wave travels in one second, measured in meters per second (m/s).
• Wavelength (λ): The distance between identical points on adjacent waves, like two crests or troughs.

The relationship between period, frequency, wavelength, and wave speed is expressed as:

• Wave speed (v) = Wavelength (λ) x Frequency (f)
• Frequency (f) = 1/Period (T)

For example, a wave with a frequency of 2 Hz means 2 waves pass a point per second, making the period 0.5 seconds.