Wave Speed Flashcards
(36 cards)
What is wave speed?
The speed at which a wave transfers energy from one place to another varies according to the medium through which it propagates.
Wave speed is denoted by the letter v.
What is the relationship between wavelength and frequency in a given medium?
Waves travel at a fixed speed, and the relationship can be calculated using the equations: f = V/n and 1 = V/F.
Here, f is frequency, V is wave speed, and n is wavelength.
What does travelling one wavelength take in terms of periodic time?
One cycle, which is one periodic time, T.
This indicates the time it takes for one complete wave to pass a point.
What is the wave equation?
v = nT = f.
This equation relates wave speed, wavelength, and frequency.
How can you tune musical instruments with strings without changing their length?
By making changes to the medium (the string), altering the speed of the waves, v.
This includes modifying thickness or tension of the strings.
What effect does a thicker string have on wave speed?
It gives a slower speed and hence a lower note.
Thicker strings have more mass per unit length.
What effect does more tension in a string have on wave speed?
It gives a faster speed and hence a higher note.
Tension is a force measured in newtons (N).
What is the equation for wave speed in strings?
v = v(T/u).
Here, T is the tension force and u is the mass per unit length.
What is the speed of light in free space (vacuum)?
2.998 × 10^8 m/s, represented by the letter c.
This is the maximum speed at which information or matter can travel.
What is the refractive index of a medium?
The ratio of the speed of light in vacuum (c) to the speed of light in the medium (v), represented as n = c/v.
The refractive index indicates how much light slows down in a medium.
What happens to light when it moves from air into water?
It moves more slowly, causing refraction.
This bending of light occurs due to the change in speed as it enters a different medium.
What are wave-fronts?
Lines (or surfaces) that represent points of a wave where the phase is the same.
Wave-fronts are spaced evenly and move forward with the wave.
What is interference in the context of waves?
The superposition of different waves causing large and small amplitudes.
This can result in constructive or destructive interference.
True or False: Sound travels faster in water than in air.
True.
The speed of sound is greater in denser media like water compared to air.
Fill in the blank: The speed of sound in air is approximately _______ m/s.
3.0 × 10^2.
This speed can vary slightly based on temperature and pressure.
What is the frequency of sound if the wavelength in air is 1.2 m and the speed of sound is 3.0 × 10^2 m/s?
f = V/n, f = 3.0 × 10^2 / 1.2.
This calculation will yield the frequency in Hz.
How much slower will waves be travelling if a guitar string is tuned to produce an open note one octave lower?
Half the frequency.
This requires adjusting the tension or mass per unit length of the string.
What is the speed of light when it travels through glass with a refractive index of n = 1.48?
c/n = 2.998 × 10^8 / 1.48.
This calculation gives the speed of light in the glass.
What is wave speed?
The speed at which a wave transfers energy from one place to another varies according to the medium through which it propagates.
Wave speed is denoted by the letter v.
What is the relationship between wavelength and frequency in a given medium?
Waves travel at a fixed speed, and the relationship can be calculated using the equations: f = V/n and 1 = V/F.
Here, f is frequency, V is wave speed, and n is wavelength.
What does travelling one wavelength take in terms of periodic time?
One cycle, which is one periodic time, T.
This indicates the time it takes for one complete wave to pass a point.
What is the wave equation?
v = nT = f.
This equation relates wave speed, wavelength, and frequency.
How can you tune musical instruments with strings without changing their length?
By making changes to the medium (the string), altering the speed of the waves, v.
This includes modifying thickness or tension of the strings.
What effect does a thicker string have on wave speed?
It gives a slower speed and hence a lower note.
Thicker strings have more mass per unit length.
