Wave basics
What is a wave, and what does it transfer?
A wave is a disturbance that transfers energy from one place to another without transferring matter.
In a transverse wave, how do particles move compared to the direction of the wave?
Answer: Particles move perpendicular (up and down) to the direction the wave travels.
Give an example of a longitudinal wave. Explain why it is longitudinal.
particles move parallel to the direction of the wave.
What does frequency measure?
Answer: Frequency measures how many waves pass a point in one second (Hz).
Which electromagnetic wave has the longest wavelength?
radio waves
What is a medium? Name one example.
Answer: A medium is the material through which a wave travels. Example: air, water, rope, or solid ground.
What are the highest and lowest points of a transverse wave called?
Answer: Crest (highest point) and trough (lowest point).
What are compressions and rarefactions?
Answer: Compressions are areas where particles are close together; rarefactions are areas where particles are spread apart.
What happens to frequency when wavelength decreases?
Answer: Frequency increases when wavelength decreases.
Which electromagnetic wave has the highest energy?
Gamma rays
Why can sound waves not travel through space?
Answer: Sound waves need a medium to travel, and space is a vacuum with no particles.
What is amplitude, and what does it tell us about a wave?
Answer: Amplitude is the height of the wave from the rest position and shows how much energy the wave has.
In which direction do particles move in a longitudinal wave?
Answer: Particles move back and forth parallel to the direction the wave travels.
what is the formula for wave speed?
Answer: Wave speed = wavelength × frequency
Why can electromagnetic waves travel through space?
Answer: They do not require a medium and can travel through a vacuum.
What is the difference between a mechanical wave and an electromagnetic wave?
Answer: Mechanical waves require a medium (like sound or water waves), while electromagnetic waves do not (like light or radio waves).
Give an example of a transverse wave. Explain why it is transverse.
particles move perpendicular to the direction of the wave.
How is wavelength measured in a longitudinal wave?
Answer: Wavelength is measured from one compression to the next compression or from one rarefaction to the next.
Two waves travel through the same medium. One has a higher frequency. Which wave has a shorter wavelength, and why?
Answer: The wave with the higher frequency has the shorter wavelength because wave speed is constant in the same medium.
Why are longer-wavelength radio waves better for long-distance communication than shorter-wavelength waves?
Answer: Longer-wavelength radio waves can travel farther and around obstacles more easily with less energy loss.
Explain why waves transfer energy but not matter.
Answer: Particles only vibrate around their original position; the energy moves, not the particles themselves.
Explain why increasing amplitude increases the energy of a transverse wave.
Answer: Greater amplitude means the particles move more, which means more energy is transferred.
Explain how sound can travel through air without air particles permanently moving forward.
Answer: Air particles vibrate in place, passing energy to nearby particles without moving forward overall.
Which electromagnetic wave has the greatest wave speed
They all go at the speed of light
List the electromagnetic spectrum in order from lowest energy to highest energy.
Radio → Microwaves → Infrared → Visible Light → Ultraviolet → X-rays → Gamma rays