Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 4 - Waves (4.6 - More about stationary waves on a string (The…
Chapter 4 - Waves
-
4.2 - Measuring waves
Key terms
The amplitude of a wave is the maximum displacement of a vibrating particle. For a transverse wave, this is the height of a wave crest or the depth of a wave trough from its equilibrium position.
The wavelength of a wave is the least distance between two adjacent vibrating particles with the same displacement and velocity at the same time.
The displacement of a vibrating particle is its distance and direction from its equilibrium position
-
-
The frequency of a wave is the number of cycles of vibration of a particle per second, or the number of complete waves passing a point per second.
Wave speed
Wave speed, c = frequency x wavelength
Phase difference
-
The phase of a vibrating particle at a certain time is the fraction of a cycle it has completed since the start of the cycle
4.3 - Wave properties 1
Refraction
When waves pass across a boundary at which the wave speed changes, the wavelength also changes. If the wavefront approaches at an angle to the boundary, they change direction as well as changing speed. This effect is known as refraction
Reflection
Straight waves directed at a certain angle to a hard flat surface reflect off at the same angle. The angle between the reflected wavefront and the surface is the same as the angle between the incident wavefront and the surface
Diffraction
Diffraction occurs when waves spread out after passing through a gap or round an obstacle. The effect can be see in a ripple tank when straight waves are directed at a gap.
-
4.4 Wave properties 2
-
Stationary waves are formed on a rope if two people send eaves continuously along a rope from either end.
The two sets of waves are referred to as progressive waves to distinguish them from stationary waves.
They combine at fixed points along the rope to form points of no displacement or nodes along the rope, at each node the two sets of waves are always 180 degrees out of phase so they cancel each other out.
-
-
-