CH 11: General Wave Properties I - Introduction

• Waves transfer energy through vibration or oscillation, with energy being transferred in the direction of wave motion but not the method.
• There are two types of waves: transverse waves, which have vibrations perpendicular to the direction of travel of the waves, and longitudinal waves, which have vibrations parallel to the direction of travel of the waves.
• Transverse waves can be produced by moving your hand up and down, while longitudinal waves can be produced by stretching a spring and moving to the right several times.
• The peak of a transverse wave is called the crest, and the minimum point of the wave is called the trough.
• The ripple will bend towards the normal when it travels from deep water to shallow water, hence i is greater than r.
• The depth of water affects the speed of a wave, hence wavelength will be affected as well.
• The deeper the water, the less resistance the wave will experience, hence the wave can travel faster or at a higher speed.
• Wavelength increases as the water gets shallower, and decreases as the water gets deeper.
• The speed of a wave is dependent on wavelength, hence v equals to lambda.
• The refraction of a wave in river tank occurs when the reaper enters the glass block at a certain angle.
• Wavelength is dependent on the wave source, usually a constant, hence v equals to f lambda.
• When the ripper enters the deep water again, it will bend away from the normal, hence i will be less than r.
• Longitudinal waves can be represented by the current state of particles, with the vertical dotted line being the neutral position for the particle.
• When a particle is at its neutral position, it is moving to the left, but when it reaches the leftmost position, it will change direction and move to the right.
• The process repeats until the particle reaches the rightmost position, at which point it will change direction and start to move to the left.
• The waveform from longitudinal waves can be plotted by taking the neutral position and marking it at 0.
• The period t is the amount of time taken for one complete cycle.
• The distance from the central position to the maximum displacement is also referred to as the amplitude.
• The river tank experiment is conducted in the lab to study waves.
• The distance from point b to point c in the river tank experiment is also the wavelength lambda.
• The maximum displacement from rest or central position is referred to as the amplitude.
• The distance from the central position to the peak or the minimum displacement is also referred to as the amplitude.
• The river tank is made of transparent glass, filled with water, and a deeper is placed at a specific position.
• The formula for the speed of wave can be rearranged to be b equals to f lambda.
• A piece of white paper is placed at the bottom of the river tank and a lamp is shone from the top, so that the reaper shadow can be observed on the white paper.
• The distance between the crest to crest is referred to as the wavelength lambda.
• The distance from point a to point d in the river tank experiment is the wavelength lambda.
• The speed of wave v is the distance travelled by wave per unit time, therefore the formula will be v equals to wavelength lambda over t.
• The dipper in the river tank experiment is connected to a motor which vibrates at a frequency of 50 hertz, producing a series of reapers that move in a specific direction.
• The distance from point c to point d in the river tank experiment is also the wavelength lambda.
• The distance between any two consecutive points that are in phase is referred to as the wavelength lambda.
• The frequency f is the number of complete cycles per unit time which is in second, the SI unit for frequency is hertz, f equals to 1 over t.
• If the dipper in the river tank experiment is in spherical shape and it moves up and down, it will produce circular reapers.