Waves Flashcards
What is wavelength?
Distance between 2 consecutive peaks or troughs
What is amplitude?
Maximum displacement of a particle from the equilibrium
What is peak and trough?
Peak- maximum positive displacement
Trough- maximum negative displacement
What is frequency?
Number of waves in one second
What is time period?
Time taken for one complete wave
What is the formula for frequency and time period?
F=1/T
T=1/F
What is a transverse wave?
When the direction of a particle vibration is perpendicular to the direction of travel of wave
E.g. light/ electromagnetic
What is longitudinal?
When the direction of a particle vibration is parallel to the direction of travel of wave
E.g. sound/ultrasound
Different parts of a wave
Peak/crest,wavelength,trough and amplitude
Three points on the analogy between water waves and light waves
Reflected wavelength = incident wavelength
Reflected frequency = incident frequency
Reflected speed = incident speed
What is an echo and what is the calculation for an echo?
Echo is a reflected sound
Speed =distance/time
(Remember to half the time as it is an echo)
What is ultrasound and what are some uses for it?
High frequency sound that is above 20kHz which is above the human hearing range.
Detecting faults in metals, cleaning delicate equipment and breaking kidney stones.
What is sonar and radar used for?
Sonar: Detects underwater objects using sound pulses
Radar: Detects aircraft’s and ships using electromagnetic waves
What do all the waves in the electromagnetic spectrum have in common?
Transverse waves
Can travel though a vacuum
Travel at the same speed (Speed of light)
Waves in order of increasing frequency and decreasing wavelength
Radio waves, micro waves, infrared waves, visible light, ultra violet waves, x-rays, gamma rays
What are the dangers of gamma rays and x-rays?
Damage cells and disrupt DNA, which may lead to cancer
What are the dangers of Ultra violet light?
Certain wavelengths can damage skin cells, disrupt DNA and may lead to skin cancer
What are the dangers of visible light?
Damage the eyes
What are the dangers of microwaves?
Internal heating of body tissues which can lead to eye cataracts.
What the dangers of infrared light?
Felt as heat and can cause burns.
What are the dangers of radio waves?
Believed to cause cancer,leukaemia and other disorders.
What do waves do in shallow water?
Travel slower.
Shorter wavelength.
Same frequency
