Jeopardy Rules. State your answers in the form of a question. Teams are chosen randomly to select each clue. When a team selects a clue, every team solves it. If the team who selects the clue is incorrect, another randomly selected team gets to try, until the answer is found.
Choose a category.
You will be given the answer.
You must give the correct question.
This wave property is the inverse of the period of a wave.
What is the frequency?
f = 1/T
A particle in a transverse wave oscillates about this place.
What is its equilibrium position?
A longitudinal wave is composed of these types of regions.
What are compressions and rarefactions?
Compressions are regions of high pressure. Rarefactions are regions of low pressure.
A wave pulse traveling down a rope is measured to be 0.3 m from trough to crest. The amplitude of the pulse is this.
What is 0.15 m?
Amplitude is measured from the equilibrium position. If crest to trough is 0.3 m, then A = 0.3m/2 = 0.15 m.
A beach goer observes a set of 6.5 ocean waves equaling the length of a 26 m dock. The wavelength of a wave is this.
What is 4 m?
If 6.5 waves have a length of 26 m, then 1 wave has a wavelength of 26 m/6.5 = 4 m
A transverse wave passes through a uniform medium from left to right. The vibration of the particles is in this direction.
What is up and down?
In a transverse wave, the particles move perpendicular to the direction of the propagation.
A sound wave is traveling at 345 m/s.
If it has a wavelength of 1.5 meters,
this is its period.
What is 0.0043 s?
v=f*λ to solve for f and then the period T = 1/f.
The energy of a mechanical wave is related to this.
What is the amplitude?
Like a stretched spring with energy 1/2kx2 (i.e. energy ∝ x2, withx the displacement from equilibrium) , the energy of a wave is proportional to A2 (with A the displacement from equilibrium).
When a wave travels in a single medium, this remains constant. When a wave crosses a boundary, this remains constant. (2 part answer)
What are speed and frequency?
A wave’s speed is constant in one medium, but it’s frequency remains constant when crossing a boundary.
Red light produces a 2 slit diffraction pattern with some ∆X. In order to produce a pattern with the same ∆X using purple light, this must happen to the distance between slits, all other variables remaining constant.
What is decrease?
λpurple is shorter than red, so ∆X will decrease. Thus, d must decrease to increase ∆X.
By increasing the frequency of a sound, you are increasing this.
What is the pitch?
The pitch of a sound is measured by its frequency.
Whenever you listen to a particular song, the glass in your coffee table vibrates loudly. The vibrations are due to this effect.
What is resonance?
When a frequency matches the natural frequency of a system, it stimulates oscillations in that system.
Polarized sunglasses block glare off of water because the polarization of the reflected light is oriented this way with the transmission axis of the polarizer.
What is perpendicular?
Light reflected off of non-metallic surfaces is polarized in the plane of the surface. If the transmission axis of the polarizer is perpendicular to the plane, the light will be blocked.
These properties change when a wave reflects off a barrier.
What are direction and phase?
Reflected waves from a fixed boundary are 180° out of phase with the incident wave and obey the law of reflection.
In Lake 1, waves with λ=0.3m pass through an opening with width 0.25m. In Lake 2, waves with λ=0.5m pass through an opening with width 2.0 m. Waves in this lake undergo more of this effect. (2 part answer)
What is Lake 1, diffraction?
Noticeable diffraction occurs when the wavelength is comparable in size to the opening.
This is the part of a standing wave with maximum amplitude.
What is an antinode?
An antinode is the place on a standing wave with maximum constructive interference.
When a water wave passes from deep water to shallow water, it bends in this direction.
What is toward the normal?
Waves travel slower in shallow water. When they Slow down, they bend Toward the normal.
(this is the S.T. in F.A.S.T.)
A 1500 Hz sound wave travels from oil into water. Compared to its wavelength in oil, its wavelength in water is this.
What is shorter?
Water is denser, so the wave speed decreases. Since v=f*λ, and frequency is constant, λ must decrease.
The fourth harmonic of a standing wave on a string has a wavelength of 20 cm. If the speed of these waves is 8.0 m/s, the frequency of the fundamental is this.
What is 10 Hz?
Fourth Harmonic: n=4
f4=v/λ=(8 m/s)/(0.2 m) = 40 Hz
f4=4f1 so f1=f4/4=(40 Hz)/4 = 10 Hz
The wavelength of light must be much smaller than a millimeter because of this observation.
What is light only diffracting through slits much smaller than a millimeter?
Light does not diffract through 1 mm slits, because the size of the gap is not comparable to the wavelength.
When two troughs of two waves meet, you get this type of interference.
What is constructive interference?
Constructive interference happens any time either two crests or two troughs meet, resulting in a wave of higher amplitude than either of the individual waves alone.
The conditions for complete destructive interference of two waves is this. (2 part answer)
What are 180° out of phase and equal amplitudes?
The waves must be out of phase and have equal amplitudes, or the destructive interference will only be partial.
The name of the nodal line for which the path difference is 2.5 Lambda is this.
What is the 3rdorder minimum (n=2)?
Nodal path difference: PD = (n+0.5)λ
PD = 2.5λ = (n+0.5)λ
n=2, 3rd order minimum.
Plane sound waves of λ = 0.5 m are incident on two narrow slits. At point P is a first order maximum, which is 6 m from the center of the slits and 6 m from the central maximum. The distance between the slits is this.
What is 0.5 m?
λ=0.5 m, D1=6 m, X1=6 m
=0.5 m*6 m/6 m = 0.5 m
If a 2 slit interference pattern from a 532 nm laser has a spacing of 0.8 cm, what is the linear displacement from the central maximum to the 3rd order minimum?
What is 2.0 cm?
∆X=0.8cm. 3rd order minimum is the nodal line n=2, which is 2.5 intervals from the central maximum. 2.5*∆X=2.5*0.8cm = 2.0cm.