Lesson 10: Chapter 10 Waves

Reflection

- act of bouncing off a surface - echo is reflection of sound - mirror is reflection of light

Refraction

- act of changing direction when passing from one medium to another - because waves travel at dif. speeds in dif. mediums the wave in the new medium changes speed and bends - glasses, microscopes, etc. - sound waves refract in dif. temperatures - change in medium

Interference

- canceling and enhancing effect that occurs when two waves move through the same space at the same time

Doppler Effect

- change in the observed frequency of a wave occurring when the source and observer are in motion relative to each other - shift in frequency of a wave - caused as the source moves toward you or away from you - siren when it moves past you

Diffraction

- changing of direction of waves to bend around corners and spread as they encounter obstacles - amount of diffraction depends on the size of the opening/obstacle and size of the wave - medium stays the same

Standing Waves

- characterized by lack of vibration at certain points between which areas of maximum vibration occur - if waves moving right and left have the same amplitude they produce standing waves - wave still moves but locations of constructive and destructive interference are stationary - get nodes and antinodes

Wavelength

- distance between successive similar parts in a repeating wave

Antinode

- location of maximum vibration in a standing wave - constructive interference

Node

- location of no vibration in standing wave - destructive interference

Compression Wave

- longitudinal wave driven by the force of pressure - created when a medium is disturbed along the direction the wave travels - forces push atoms closer together and move them farther apart - sound waves

Amplitude

- max. amount that a particle will displace from its normal, undisturbed position when a wave passes through it - amplitude of light is brightness - amplitude of sound is loudness

Frequency

- number of wave amplitude crest that pass a particular joint in space every second - in a given medium wavelength and frequency are related inversely

Wave Speed

- rate at which a specific wave disturbance travels from point to point - wave speed = wavelength x frequency - changes only when a wave passes from one medium to another or when some characteristic of a medium changes

Shear Wave

- transverse wave driven by shearing forces between molecules - disturbance is perpendicular to the direction the wave is moving - created by sideways forces - can't exert shear forces on liquids, gases, or plasmas because atoms aren't rigidly bound together - wave at football stadium

Transverse Wave

- wave in which the molecules of the medium vibrate at right angles to the direction the wave propagates

Longitudinal Wave

- wave in which the molecules of the medium vibrate in the same direction as the wave propagates

Surface Wave

- wave that travels along the surface of a medium - water waves - transverse wave doesn't travel through the medium but along boundary between two types of mediums

Water waves bending as they pass a jetty by a shore. A. reflection B. refraction C. diffraction D. interference

diffraction

Waves may be observed to reflect, refract, diffract, and interfere. Two of these behaviors are unique to waves only and two of them may also be observed for particles (or convincingly counterfeited by particles). Which two are wave behavior only? Select one: A. reflection and refraction B. diffraction and reflection C. reflection and interference D. refraction and diffraction E. interference and refraction F. diffraction and interference

diffraction and interference

Laser light passing through narrowly spaced slits and forming a pattern of light and dark spots on a screen. A. reflection B. refraction C. diffraction D. interference

interference

As you change the frequency what happens to the wave? A. It changes height up-and-down. B. It changes width left-to-right. C. It changes speed.

it changes width left to right

As you increase the amplitude what happens to the wave? A. It gets taller up-and-down. B. It gets wider left-to-right. C. It gets faster.

it gets taller up and down

If the pictures 1 and 2 are snapshots of a water wave and a wave on a string, respectively, what can you conclude about the frequency of the two waves? A. The first wave has a higher frequency. B. The second wave has a higher frequency. C. The two waves have the same frequency. D. It is not possible to determine anything about frequency from the still pictures.

it is not possible to determine anything about frequency from the still picture

Person seeing themselves in a mirror. A. reflection B. refraction C. diffraction D. interference

reflection

Suppose you are in a room with no windows and no lights on but the door is open. Light from the hall fills most of the room. The light entering the room can best be explained by: A. diffraction B. interference C. reflection D. refraction

reflection

Light being focused by a lens. A. reflection B. refraction C. diffraction D. interference

refraction

If you change how loud a sound wave is, what are you changing? A. The amplitude B. The frequency C. The wavelength D. The wave speed

the amplitude

The pictures 1 and 2 are snapshots of two different water waves moving through the same depth of water. What can you conclude about the frequency of the two waves? same pic as before A. The first wave has a higher frequency. B. The second wave has a higher frequency. C. The two waves have the same frequency. D. It is not possible to determine anything about frequency from the still pictures.

the first wave has a higher frequency

The pictures 1 and 2 are snapshots of two different water waves moving through the same depth of water. What can you conclude about the frequency of the two waves? wave 1 is tall and skinny wave 2 is shorter and fatter A. The first wave has a higher frequency. B. The second wave has a higher frequency. C. The two waves have the same frequency. D. It is not possible to determine anything about frequency from the still pictures.

the first wave has a higher frequency

If you change the wavelength of a sound wave, what else will change? A. The loudness B. The frequency C. The amplitude D. The speed

the frequency

If you increase the amplitude of the sound wave, what else will happen? Select one: A. The sound wave will spread out more. B. The sound wave will have a higher pitch. C. The sound wave will travel faster through the air. D. The distance between points of high pressure will become larger. E. The sound wave will become louder.

the sound wave will become louder

What can you determine about the speed of the waves in the problem above through the water? Select one: A. the speed is greater for the first wave B. the speed is greater for the second wave C. the speed is the same for both waves

the speed is the same for both waves

Two sound waves are traveling through the air. What happens at a point where two low pressure regions overlap? Select one: A. The two waves will bounce off of each other. B. The two waves will bend around each other. C. The two waves will create a new wave that spreads out from that point. D. The two waves will combine to make a louder sound at that point. E. The two waves will cancel out so that there is no sound at that point.

the two waves will combine to make a louder sound at that point

Mechanical Wave

traveling disturbance in material that transports energy

What is the term for the width of a wave left to right? A. Amplitude B. Wavelength C. Frequency D. Wave speed

wavelength