Karteikarten
Basics + Progressive Waves
Karten in diesem Stapel (41)
- 1Define a wavePeriodic disturbance in a material (medium) or space
- 2Each particle of the medium....Oscillates (or vibrates) about a fixed position
- 3Due to this oscillation, the wave transfers....Energy without any material being transferred
- 4Mechanical waves are....Motion of matter through vibrations of particles (e.g. sound waves and water waves)
- 5Electromagnetic waves are....Vibrating electric and magnetic fields that can travel through a vacuum (also the fields are oscillating)
- 6Electromagnetic spectrum:
- 7X-rays come from....Electrons
- 8Gamma rays come from....A nucleus
- 9The wavelength of red light is....7 x 10^-7 m (1sf)
700nm - 10The wavelength of blue light is....4 x 10^-7m (1sf)
400nm - 11We should know that the EM Spectrum is....Continuous
- 12Progressive waves are waves that....Move outwards from the source
- 13Displacement-distance wave graph:
- 14Define AmplitudeMaximum displacement from equilibrium position
- 15Define WavelengthHorizontal distance between either:
2 crests
2 troughs
Any 2 corresponding parts of same wave - 16Displacement-time wave graph:
- 17Time period (T) is....The time in seconds for a wave to travel a distance of 1 wavelength
- 18What is the formula for period?Frequency = 1/period
- 19Define frequencyNumber of waves passing a point per unit time (usually per second)
(1Hz = 1 per second) - 20What are the 2 units for frequency?Hz or s^-1
- 21What is the wave equation?V = fλ
(Speed ms-1 = frequency hz x wavelength m)
Note V may also be wrote as a C - 22What is the equation similar to speed distance time but used for waves?V = λ / T
(speed = wavelength x time period) - 23Define a radian:When the length of an arc equals the radius the angle is 1 radian
(2π = 360 degrees) - 24Define phaseExactly the same pattern of oscillation
- 25When in phase, the phase difference is....360 degrees
- 26Antiphase is a specific circumstance where....When out of phase, the phase difference is 180 degrees
- 27Diagram to illustrate phase:
- 28Reflection is when....Waves hit a boundary they can't pass so are reflected back
- 29When reflected, waves undergo a phase change of....180 degrees or (π rad)
- 30Reflection diagram of phase change
- 312 equations for working out phase difference:2π x (t/T) , (time difference / time period)
2π x (d/λ) , (distance / wavelength) - 32If points on a wave are in phase, the radian value of their phase difference is....2π
- 33What does the word propagation mean?Movement
- 34For transverse waves, the direction of wave propagation is.....Perpendicular to oscillations
- 35For longitudinal waves, the direction of wave propagation is....Parallel to oscillations
- 36Compression and rarefaction diagram:
- 37On a model of longitudinal wave, what do the peaks and troughs represent?Peaks = compression
Troughs = rarefactions - 38Examples of transverse waves:EM waves, water waves , waves on string, S-waves (secondary , seismic)
- 39Examples of longitudinal waves:Sound waves , P-Waves (seismic)
- 40In the wave equation , v=fλ , what value is usually constant?v
- 41—