How Does Changing The Frequency Affect The Energy Of The Wave

Learning Objective

Discuss how wave movement arises and its measurable properties, noting the conlcusions of Immature'south double slit experiment

Primal Points

Wave motility arises when a periodic disturbance of some kind is propagated through an elastic medium. Pressure variations through air, transverse motions along a guitar cord, or variations in the intensities of the local electric and magnetic fields in space, known equally electromagnetic radiation, are all examples of waves.
There are three measurable properties of wave motion: amplitude, wavelength, and frequency.
A definitive experiment was Young'due south double slit experiment, which demonstrated that light shined at 2 slits in a screen evidence an interference pattern feature of waves of light, rather than particles.
The stage associated with a wave is besides important in describing certain phenomena.
The velocity of a wave is the production of the wavelength and the frequency.

Terms

amplitudeThe maximum value of the variable reached in either direction.
waveA shape that alternatively varies between a maximum in ii reverse directions.
frequencyThe number of vibrations per 2d.
wavelengthThe altitude traveled past the wave in a total period (1/frequency).

In this section, we volition focus on the moving ridge-like backdrop of light. While you will subsequently acquire almost wave/particle duality (how light behaves every bit both a wave and a particle at the same fourth dimension), hither we shall hash out the moving ridge nature of calorie-free and the experimental furnishings of this behavior.

Introduction to Wave Motility

Moving ridge motion arises when a periodic disturbance of some kind is propagated through a medium. Force per unit area variations through air, transverse motions forth a guitar string, or variations in the intensities of the local electrical and magnetic fields in space, which constitute electromagnetic radiations, are all typical examples of moving ridge move. For each medium, there is a feature velocity at which the disturbance travels.

**Sinusoidal wave**This paradigm shows the anatomy of a sine curve: the crest is the peak of each wave, and the trough is the valley; the amplitude is the altitude between the crest and the x-centrality; and the wavelength is the distance betwixt two crests (or 2 troughs).

There are iii measurable properties of wave motion: amplitude, wavelength, and frequency (the number of vibrations per second). The relation betwixt the wavelength λ (Greek lambda) and frequency of a wave ν (Greek nu) is determined by the propagation velocity v, such that

[latex]5=\nu \lambda[/latex]

For light, this equation becomes

[latex]\nu = \frac{c}{\lambda}[/latex]

where c is the speed of low-cal, 2.998 10 10⁸ chiliad/s.

When utilizing these equations to determine wavelength, frequency, or velocity by manipulation of the equation, it is important to notation that wavelengths are expressed in units of length, such as meters, centimeters, nanometers, etc; and frequency is typically expressed every bit megahertz or hertz (s^–1).

Instance

What is the wavelength of the musical note A = 440 hz when information technology is propagated through air in which the velocity of sound is 343 chiliad s–ane?

λ = v (343 grand due south-1)/ five(440 s–1) = 0.780 1000

Young's Double-Slit Experiment

In the early on 19th century, English scientist Thomas Immature carried out the famous double-slit experiment (also known as Young's experiment), which demonstrated that a axle of light, when split into two beams and and so recombined, will show interference effects that tin merely be explained past assuming that light is a wavelike disturbance. If light consisted strictly of ordinary or classical particles, and these particles were fired in a straight line through a slit and allowed to strike a screen on the other side, we would wait to come across a pattern corresponding to the size and shape of the slit. However, when this unmarried-slit experiment is actually performed, the pattern on the screen is a diffraction pattern in which the low-cal is spread out. The smaller the slit, the greater the angle of spread.

**Young'southward double slit experiment**If calorie-free were purely a particle, information technology would not exhibit the interference pattern shown hither.

Similarly, if light consisted strictly of classical particles and we illuminated two parallel slits, the expected design on the screen would merely be the sum of the 2 single-slit patterns. In actuality, however, the pattern changes to ane with a series of alternating low-cal and dark bands. When Thomas Young first demonstrated this phenomenon, it indicated that lite consists of waves, as the distribution of brightness can be explained by the alternately condiment and subtractive interference of wavefronts. Young's experiment, performed in the early 1800's, played a vital role in the acceptance of the wave theory of light, superseding the corpuscular theory of low-cal proposed by Isaac Newton, which had been the accepted model of light propagation in the 17th and 18th centuries. Almost a century later, in 1905, Albert Einstein'south Nobel-Prize winning research into the photoelectric effect demonstrated that light can behave as if it is equanimous of discrete particles under certain weather. These seemingly contradictory discoveries made information technology necessary to go beyond classical physics and accept the breakthrough nature of lite into account.