WAVE MOTION

BY:

AIMEE R. PAREÑO

WAVE is a disturbance that carries energy through matter or space.

MEDIUM – the matter through which wave travels.

TYPES OF WAVES:

MECHANICAL WAVESwaves that requires a medium

ELECTROMAGNETIC WAVESwaves that do not require a medium

PULSE WAVEwave that consists of a single traveling pulse

PERIODIC WAVESthe continues generation of pulses (pulse wave)

CLASSIFICATIONS OF WAVES ACCORDING TO THE DIRECTION OF MOTION OF THE MEDIUM

LONGITUDINAL WAVES – the vibrations are along the direction of the wave.

TRANSVERSE WAVES – the vibrations are at a right angle or perpendicular to the direction of the wave.

CLASSIFICATIONS OF WAVES

(A) Transverse waves

(B) Longitudinal waves

LONGITUDINAL WAVES

COMPRESSION

the region where the coils of the spring are pressed together

RAREFACTION

the region where the coils of the spring are spread out.

TRANVERSE WAVES

CRESTS

the points where the coils of the spring are at the highest.

TROUGHS

the points of the coils of the spring are at the lowest.

MEASURES OF A WAVE

WAVEFORM

a picture of a wave

AMPLITUDE

the maximum displacement of the particles of the medium from their equilibrium

WAVELENGTH the distance between neighboring

displacements The distance between two successive

crests or troughs, or between two successive compressions or rarefactions

AMPLITUDE AND WAVELENGTH OF THE A WAVE

WAVE MOTION CAN BE DESCRIBED IN TERMS OF ITS SPEED

v = λ / T and T = 1 / f then,

v = λ / 1/f therefore,

v = λf where v – velocity of the wave

λ – wavelengthf – frequency of the wave

Sample Problem

If a dog whistle has a frequency of 30 000 Hz, what is the wavelength of the sound emitted?(speed of sound = 340 m/s)

Solution:

Given: v = 340 m/s

f = 30 000 Hz = 30 000 /s

v = λf → λ = v / f

λ = 340 m/s

30 000 /s

= 0.011 m

Evaluation

Complete the table

Frequency

(Hz)

Wavelength

(m)

Velocity

(m/s)

250 2 (c)

(a) 150 3

300 (b) 150

Assignment

What is the period of the wave while Aaron is surfing if the wave propels him toward the beach with a speed of 5.0 m/s and the wave crests are 2.0 m apart?

THE END