Wavesomg!!!!!

● A mechanical wave is created when a source of energy causes a vibration to travel through a medium.

● mechanical wave: Is a disturbance in matter that carries energy from one place to another.

● The three main types of mechanical waves are transverse waves, longitudinal waves,and surface waves.○ transverse wave:Is a wave that cause the medium to vibrate at right angles to the

direction in which the waves travel.

○ longitudinal wave:Is a wave in which the vibration of the medium is parallel to the

direction the wave travels.○ Surface wave:Is a wave that travels along a surface separating two media.

Transverse,longitudinal,Surface Waves

● A wave’s frequency equals the frequency of the vibrating source producing the wave.○ Frequency: which is the number of complete cycles

in a given time.

Frequency

● Increasing the frequency of a wave decrease its wavelength.○ Wavelength:Is the distance between a point

on one wave and the same point on the next cycle of the wave.

Wavelength

● For waves traveling at a given speed, wavelength is inversely proportional to frequency .

● The more energy a wave has, the greater is its amplitude. ○ Amplitude:Is the maximum displacement of

the medium from its rest position

● A reflected wave has a smaller amplitude than the original wave because it loses some energy during reflection.○ Reflection:Does not change the speed or

frequency of a wave,but the wave can be flipped upside down

● When a wave enters a medium at an angle, refraction occurs because one side of the wave moves more slowly than other side.○ Refraction:The bending of the wave as it

enters a new medium at an angle

● The larger the wavelength is compared to the size of an opening or obstacle, the more a wave diffracts.

● The types of interferences are constructive interference and destructive interference.○ Interference:Occurs when two or more waves overlap and combine together.

○ Constructive Interference:Occurs when two or more waves combine to produce a wave with a larger displacement.

○ Destructive Interference:Occurs when two or more waves combine to produce a wave with a smaller displacements.

● A standing wave forms only if half a wavelength or a multiple of half a wavelength fits exactly into the length of the vibrating object.

● Many behaviors of sound can be explained using a few properties-speed, intensity and loudness,and frequency and pitch.○ Intensity:Is the rate at which a waves

energy flows through a given area○ Pitch:Is the frequency of a sound as you

perceive it

● Ultrasound is used in many applications,including sonar and ultrasound imaging.

● As a source of sound approaches,an observer hears a higher frequency.When the sound source moves away,the observer hears a lower frequency.

The outer ear gathers and focuses sound into the middle ear,which receives and amplifies the vibratons.The inner ear uses nerve endings to sense vibrations and send singals to the brain.

● Sound is recorded be converting sound waves into electrical signals that can be processed and stored.Sound is reproduced be converting electrial signals back into sound waves.

● Most instruments vary pitch by changing the frequency of standing waves.

● Electromagnetic waves are produced when an electric charge vibrates or accelerates.○ Electromagnetic waves:Transverse waves

consisting of changing electric fields and changing magnetic fields.

● Electromagnetic waves can travel through a vacuum,or empty space,as well as through matter.

● The speed of light in a vaccum,c, is 3.00 X 10^8 meters per seconds.

● Electromagnetic waves vary in wavelength and frequency

● Electromagnetic radiation behaves sometimes like a wave and sometimes like a stream of particles.○ Electromagnetic radiation:The transfer of

energy by electromagnetic waves traveling through matter or across space.

● The intensity of light decreases as photons travel farther from the source.

● The electromagnetic spectrum include radio waves infrared rays,visible light,ultraviolet rays, X-rays,and gamma rays.○ Electromagnetic spectrum:the full range

frequencies of electromagnetic radiation.

● Radio waves are used in radio and television technologies,as well as in microwave ovens and radar.

● Scattering:Means that light is redirected as it passes through a medium.● Opaque:Materials either absorbs or reflects all of the light that strikes.● Image:Is a copy of an object formed by reflected or refracted waves of light.● Mirage:Is a false or distorted image.● Scattering:That light is redirected as it passes through a medium.● Polarized light:Light with waves that vibrate in only one plane.● Diffuse reflection:Occurs when parallel light waves strike a surface and reflect all in the same

direction.● Regular reflection:Occurs when parallel light waves strike a rough uneven surface and reflects

in many different directions.