Wave Basics
What is the resting position of a wave called?
Equilibrium
What determines the pitch of a sound?
Frequency
Which EM wave is used in microwave ovens?
Mircowaves
What is it called when light bounces off a surface?
Reflection
What symbol represents wavelength?
λ (lambda)
When two waves combine to make a bigger wave, what is it called?
Constructive Interference
In a transverse wave, what is the highest point called?
Crest
What determines how loud a sound is?
Amplitude
Which EM wave has the highest energy?
Gamma rays
What causes a straw to appear bent in water?
Refraction
A wave has frequency 10 Hz. What is its period?
0.1 s
When two waves cancel each other out, what is it called?
Destructive interference
How are longitudinal waves different from transverse waves? (Not just the shape)
Longitudinal waves vibrate parallel to motion; transverse waves vibrate perpendicular.
What does sound travel faster in water than in air?
Particles are closer together, so energy transfers faster.
Why can UV rays damage skin cells?
They carry enough energy to damage DNA and cells, they are ionizing.
What is the angle of incidence?
The angle between the incoming ray and the normal.
A note has wavelength 1.32 m. Speed of sound is 343 m/s. Find frequency.
259.85 Hz
If two identical waves meet crest-to-trough, what happens?
They cancel out (destructive interference)
A wave has a wavelength of 4 meters and frequency of 5 Hz. What is its speed?
20 m/s
A tuning fork vibrates at 800 times in 4 minutes
3.33 Hz
Put these in order from LOWEST to HIGHEST frequency: Radio, Infrared, X-ray
Radio → Infrared → X-ray
Why does light bend when it enters water from air?
Light changes speed in different mediums.
A radio station broadcasts at 102.7 MHz. Is the period very large or very small? Explain.
Very small because very high frequency means tiny period. Big Frequency = Small Period
A satellite is 42,981,000 meters away. How long does a light signal take to reach Earth?
About 0.143 seconds
Why could my stepmom Kathy hear everything I was saying at our cabin?
Sounds travels further on cooler water.
Two speakers are playing the exact same musical note at the same frequency. A student standing in one spot hears the sound very loudly, but another student a few feet away can barely hear it. Explain what is happening.
The sound waves are interfering with each other. In some places the waves combine to make a larger amplitude (constructive interference), making the sound louder. In other places they cancel out (destructive interference), making the sound quieter.
A student says radio waves travel slower than visible light because they have lower frequency. Explain why this is incorrect.
All EM waves travel at the speed of light in a vacuum.
Compare diffraction and refraction.
Diffraction is bending around obstacles/openings; refraction is bending due to changing speed in different mediums.
If the frequency of a wave doubles, what happens to its period?
It is cut in half.
A student says waves transfer matter from place to place. Explain why this is incorrect.
Waves transfer energy, not matter. The particles mostly vibrate in place.