Waves Flashcards
What is the definition of transverse waves?
transverse waves are waves that vibrate or oscillate perpendicular to the direction of energy transfer/motion.
Give an example of a transverse wave.
Examples include ripples on the surface of water, vibrations in a guitar string, S-waves, and electromagnetic waves.
Define longitudinal waves.
Longitudinal waves are waves that vibrate parallel to the direction of energy transfer/motion.
Provide an example of a longitudinal wave.
Sound waves, P-waves, and pressure waves caused by repeated movements in a liquid or gas
What is amplitude?
Amplitude is the distance from the equilibrium position to the maximum displacement.
Explain the Doppler effect.
- The Doppler effect is the apparent change in wavelength and frequency of a wave emitted by a moving source.
- It results in compression and stretching of wavefronts.
What is the relationship between wave speed, frequency, and wavelength?
v=f×λ
List the order of the electromagnetic spectrum in terms of decreasing wavelength and increasing frequency.
Radio Waves, Microwaves, Infrared, Visible light, Ultraviolet, X-Rays, Gamma Rays.
Explain the detrimental effects of excessive exposure to ultraviolet waves.
Ultraviolet waves can cause eye damage, sunburn, and skin cancer. Protective measures include using good quality sunglasses and sunscreen.
What is the critical angle?
the angle of incidence that produces an angle of refraction of 90 degrees, leading to total internal reflection.
Describe the properties of transverse waves
- Transverse waves involve vibration perpendicular to the direction of energy transfer.
- Energy transfer occurs in the same direction as wave motion, and particles of the medium don’t transfer energy.
- Examples include ripples on water and electromagnetic waves.
How can the Doppler effect be observed in the context of a moving car?
- When a car is moving, sound wavefronts at the front of the vehicle appear squashed together, creating a shorter wavelength and higher frequency.
- Behind the car, wavefronts appear stretched out, resulting in a longer wavelength and lower frequency.
State the relationship between refractive index, angle of incidence and angle of refraction.
n = sin i/sin r
State two uses of total internal reflection.
- optical fibres for communication
- in endoscopes
State the equation linking critical angle and refractive index
Sin c = 1/index angle
Explain what is meant by the term refraction.
Refraction is the change of direction of a wave as it changes from a less dense medium to a more dense medium
Explain why the ray of light is refracted towards the normal
- Wavelength is shorter in glass
- Speed slower in glass
Explain why rays of light inside a diamond are more likely to be totally internally reflected than those inside an opal
- Larger refractive index meaning that the c is smaller
- TIR happens when i>c
- diamond therefore has a larger range of angles for TIR
Explain what is happening to the light in the glass fibre
- Light reflects inside the surface of the fibre
- with angle i > critical angle
- light is traveling slower in glass
State a similarity and difference between a transverse wave and a longitudinal wave
Similarity: They both vibrate
Difference: longitudinal waves vibrate parallel to the direction of travel, whereas, transverse waves vibrate perpendicular to the direction of energy transfer
Suggest two differences between ultrasound waves and ultraviolet waves
- Ultraviolet waves have a much higher frequency than ultrasound waves
- Ultrasound waves are slower than ultraviolet waves
State two similarities between visible, light infrared, and ultraviolet
- they all transfer energy
- They are all transverse waves
What is meant by the term wavelength?
Distance between two points on a wave
State a property of waves that is the same for radio waves and X-rays
They are electromagnetic
