WAVES Flashcards
(23 cards)
What is a progressive wave?
A progressive wave carries energy from one place to another without transferring any material.
What are the two types of progressive waves?
Transverse waves (oscillation is perpendicular to energy transfer) and longitudinal waves (oscillation is parallel to energy transfer).
What is displacement in the context of waves?
Displacement is how far a point on the wave has moved from the undisturbed position.
What is amplitude?
Amplitude is the maximum magnitude of displacement.
What is phase in wave terminology?
Phase is the measurement of the position of a certain point along the wave cycle.
How is phase difference calculated?
Phase difference in radians = 2πd for distance d apart λ.
What are polarised waves?
Polarised waves oscillate in only one direction.
What is required for polarisation to occur?
Polarisation can only happen for transverse waves.
What does a polarising filter do?
A polarising filter only transmits waves in one plane.
What is superposition in wave theory?
Superposition occurs when two or more waves pass through each other, combining their displacements.
What is the principle of superposition?
The resultant displacement equals the vector sum of the individual displacements.
What is a stationary wave?
A stationary wave is the superposition of two progressive waves with the same frequency/wavelength, and no energy is transferred.
What is the relationship between nodes and antinodes in stationary waves?
A node is a point of zero displacement, while an antinode is a point of maximum displacement.
What factors affect the resonant frequency of a string?
The longer, heavier, or looser the string, the lower the resonant frequency.
What is the formula for the fundamental frequency of a string?
ƒ0 = 1/2l √(T/μ), where l is the fixed length of the string, T is tension, and μ is mass per unit length.
What happens when two progressive waves are in phase?
They reinforce each other to create a larger wave.
What occurs when waves are in antiphase?
They cancel each other out.
What is the phase difference between two particles at adjacent nodes?
0 or 2π if between adjacent nodes or separated by an even number of nodes.
What is the phase difference if particles are separated by an odd number of nodes?
π.
How do particles in a stationary wave vibrate?
All particles except those at the nodes vibrate at the same frequency.
How does amplitude vary in a stationary wave?
Amplitude varies from zero at nodes to maximum at antinodes.
What is the phase difference between two particles in a stationary wave?
Phase difference = nλ, where n is the number of nodes between the particles.
What is the phase difference in a progressive wave?
Phase difference = 2πd/λ.
