Vocabulary
What is a wave?
A wave is a disturbance that transfers energy.
What do waves transfer from place to place?
Waves transfer energy from place to place.
What is frequency?
Frequency is the number of waves that pass a point in a certain amount of time.
What happens during reflection?
Reflection happens when a wave bounces off a surface.
What is the normal line?
The normal line is an imaginary line perpendicular to a surface where a ray strikes.
In your own words, what does amplitude describe?
Amplitude describes the height of a wave from its resting position.
In your own words, describe how particles move in a transverse wave compared with the direction the wave travels.
In a transverse wave, particles move perpendicular to the direction the wave travels.
In your own words, what does wavelength measure?
Wavelength is the distance between matching points on a wave.
In your own words, what is an echo?
An echo is sound that reflects off a surface and returns to the listener.
From what line are the angles of incidence and reflection measured?
The angles of incidence and reflection are measured from the normal line.
A wave passes a point several times during a short period. What wave property tells how many waves pass that point in a certain amount of time?
Frequency tells how many waves pass a point in a certain amount of time.
A wave travels forward while its particles move perpendicular to that direction. What kind of wave is it?
It is a transverse wave.
A wave’s frequency increases while it travels through the same medium under the same conditions. What happens to its wavelength?
The wavelength becomes shorter.
A student shouts near a wall and hears the sound again. What happened to the sound waves to produce the echo?
The sound waves bounced off the wall and returned to the student.
A light ray hits a mirror at 30° from the normal line. What is its angle of reflection?
Its angle of reflection is 30° because the angle of reflection equals the angle of incidence.
Explain the difference between amplitude and wavelength.
Amplitude is the height of a wave from its resting position, while wavelength is the distance between matching points on a wave.
Explain what happens to the energy carried by a wave when its amplitude increases.
When a wave’s amplitude increases, the wave carries more energy.
Compare how wavelength changes when frequency increases with how it changes when frequency decreases in the same medium under the same conditions
In the same medium under the same conditions, a higher frequency means a shorter wavelength, while a lower frequency means a longer wavelength.
Explain how an echo is produced, including what happens to the sound waves before they return to the listener.
An echo is produced when sound waves bounce off a surface and return to the listener.
Compare the reflection of light from a smooth surface with its reflection from a rough surface.
A smooth surface produces regular reflection, while a rough surface produces diffuse reflection, with light reflecting in many directions.
A student describes wavelength as the height of a wave and amplitude as the distance between matching points. Explain how to correct both parts of the student’s description.
The student should switch the definitions: amplitude is the height of a wave from its resting position, and wavelength is the distance between matching points on a wave.
A student increases the amplitude of a wave on a spring. Explain what changes and what does not change about the wave’s energy transfer and the particles’ motion.
Increasing the amplitude means the wave carries more energy. In a transverse wave, the particles move perpendicular to the direction the wave travels; the wave transfers energy as it travels.
Two waves travel through the same medium under the same conditions. Wave A has a lower frequency than Wave B. Which wave has the longer wavelength? Explain why.
Wave A has the longer wavelength because it has the lower frequency. In the same medium under the same conditions, lower frequency corresponds to longer wavelength.
A student hears an echo after shouting near a wall. Explain the path of the sound that accounts for the echo, and clarify whether the wall creates new sound waves or reflects the original sound.
The original sound waves travel to the wall, reflect off it, and return to the student. The wall reflects the sound; it does not create new sound waves.
A student measures the angle of incidence from the surface instead of the normal line. Explain the mistake, and describe how a rough wall and a mirror differ in the way they reflect light.
The student should measure the angle from the normal line, not from the surface. The angle of incidence equals the angle of reflection when both are measured from the normal line. A rough wall produces diffuse reflection in many directions, while a mirror’s smooth surface produces regular reflection in an orderly way.