Waves Flashcards
(19 cards)
All waves transfer what from one point to another through vibrations, some waves transfer what
Energy, Information
Transverse wave definition and examples
A wave in which the vibrations are perpendicular to the direction in which the wave travels. Water Waves, secondary earthquake waves, All 7 regions of the ‘em spectrum
Displacement distance Graph d/m
Peak/crest to peak/crest is wave length
Up to peak One A - amplitude
Peak to trough 2A
Displacement time graph t/s
Peak/crest to peak/crest is time period
Up to peak One A - amplitude
Peak to trough 2A
F = 1/t
F- frequency Hz
t- time period s
Longitudinal wave definition and examples
A wave in which the vibrations are parallel in the direction of the travel of the wave. Sound, Ultrasound and Primary Earthquake Waves.
Parts of a Longitudinal wave
Sections pushed together called compressions
Sections stretched out called rarefactions
Wave equation
V = f x (\
(\ = wavelength in m
V = speed in m/s
f = frequency in Hz
Hearing range
20Hz to 20,000Hz
Ultrasound definition
Sound waves that have frequency’s above 20,000Hz
Uses of Ultrasounds
To measure formal head diameter
In industry to detect defects in metal
Mechanical and electromagnetic waves are produced how?
Mechanical - a disturbance in a material medium
‘‘Em - a disturbance in the form of a varying electric and magnetic field.
All Em waves
Travel at the same speed in a vaccum at 300,000,000m/s
Are transverse waves
Electromagnetic spectrum
Em waves from a continuous order of changing wavelength, frequency and energy.
(Lowest wavelength, frequency, energy) Radio waves, microwaves, infrared, visible light, UV, X-rays, Gamma rays (highest wavelength, frequency, energy)
Uses of The EM Spectrum
Radio waves - Bluetooth and radios in cars
Microwaves - heating food and mobile phones
IR - sensors on cars for reversing
Visible light - seeing things
UV - detecting forged bank notes
X-ray - detecting broken bones
Gamma rays - In medical imagery such as pet scans
Overexposure to certain types of EM radiation can be harmful, the higher the frequency of the radiation, more damage to the body. Give examples
Microwaves - causes internal heating of body tissues
IR- Fealt as heat and causes skin burn
Certain wavelengths- By UV can damage skin cells, lead to skin cancers
Intense visible light- can damage eyes
X-rays and Gamma rays- damages cells, lead to cancer
Frequencies on a graph. Higher number of waves equals? And low number of waves equals?
High number of waves: high frequency and high pitch
Low number of waves: low frequency and low pitch
4 points on the reflection of water waves
Incident ray + arrow
Normal at 90 degrees
Reflected ray + arrow
I= R - (wavelength constant)
Look at refraction of water waves
