Waves Flashcards
What is a wave
An osscillation (movement back and forth) or vibration that transfers energy or information.
Features of a wave
Amplitude, frequency and wave length
Amplitude meaning
The distance from the middle to the top or bottom of a wave.
Frequency meaning
The number of waves that go past a particular wave in a second.
Wave length meaning
The distance from one point of a wave to the same point on the next wave.
What is the top of a wave called
Peak or crest
What is the bottom of a wave called
Trough
What is a transverse wave
Oscillation is at 90 degrees to the direction of the wave.
Longitudinal wave
Oscillation is parallel to the direction of the wave.
Compression wave
The coils of the spring are close together.
Rarefaction
Coils are further apart.
Reflecting waves
Waves bounce off surfaces and barriers just like a football bounces off a ball. This is reflection
Incident wave
The wave coming into the barrier
Reflected wave
The wave bouncing off
Adding waves
When waves are put together they superpose. This means they add up or cancel out.
What is a soundwave
A vibration produces a soundwave eg speakers/headphones.
What does sound travel through
Sound needs a medium like a solid, liquid or gas to travel through. It cannot travel through an empty space like a vacuum because there are no empty spaces.
How does sound travel
Air molecules move backwards and forwards
How fast does sound travel
Sound travels faster in solids because their particles are closer together, so the vibration is passed along quicker.
What travels faster: sound or light
Light travels faster - light can travel through a vacuum it doesn’t need a medium.
What affects loudness of a sound eg if you band a drum harder
You produce a louder sound, this has a bigger amplitude and transfers more energy
What affects the pitch of a sound
Frequency
High pitched sounds have a high frequency
Low pitched sounds have a low frequency
How is frequency measured
kilohertz (kHz) or hertz (Hz)
1 kHz = 1000Hz
What does audible range mean
You can only hear a particular range of frequencies
You have the biggest audible range when you are young
Infrasound
Frequencies below 20Hz
Ultrasound
Frequencies above 20,000Hz
The Ear Parts
Pinna - part of the ear you can see
