Flashcards
Standing Waves
Flashcards do conjunto (22)
- 1Standing waves are also referred to as.....Stationary Waves
- 2Essentially, a standing wave is.....The superposition of 2 progressive waves travelling in opposite directions producing a standing wave
- 3The 2 progressive waves in superposition should have the same.....Amplitude and frequency
- 4How is a standing wave formed (exam answer) ?Incident wave send down string
It's then reflected at the fixed end
This reflected wave and another incident wave superpose
The incident and reflected waves have the same amplitude and frequency
Producing pattern of nodes and anti-nodes
AKA standing waves - 5What are the properties of a node on a standing wave?It has 0 amplitude (is always stationary)
- 6What are the properties of an anti-node on a standing wave?It has maximum amplitude (is always oscillating)
- 7Standing wave diagram:
- 8The first harmonic (fundamental frequency) standing wave has what wavelength?λ / 2
- 9The second harmonic standing wave has what wavelength?λ
- 10The third harmonic standing wave has what wavelength?1.5 λ
(this pattern continues) - 11Harmonic standing wave diagram:
- 12For standing waves, which value of the wave equation (v=fλ) is fixed?v (wave speed)
- 13What is the equation for finding the first harmonic frequency (fundamental frequency) ?f = 1/2l x root(T/μ)
f = fundamental frequency Hz
l = length of string m
T = tension in string N
μ = mass per unit length kgm-1 - 14How do we work out tension?T = mass (on string) x gravity
- 15How do we work out mass per unit length?μ = M / L
M = mass of string
L = length of string
Note m and M are not the same!!!!! - 16Diagram for phase of standing wave:
- 17Amplitude on progressive wave is.....A constant value equal to amplitude
- 18Amplitude on a standing wave.....Varies from 0 to max amplitude
- 19Phase on a progressive wave.....Constantly varies
- 20Phase on a standing wave:In phase with adjacent nodes
In anti-phase with adjacent sections - 21Energy on progressive waves:Transferred in direction of travel
- 22Energy on standing waves:Stored in wave