Chapter 18 Wave motion
Chapter 18 Wave Motion
18-1 Mechanical waves eIn this chapter, we consider only mechanical waves such as sound waves. water waves and the waves transmitting in a guitars strings. Elastic mediums are needed for the travel of mechanical waves Mechanical waves can appear when an initial disturbance is made to the mediums On a microscopic level, the forces between atoms in the mediums are responsible for the propagation of the waves
18-1 Mechanical waves In this chapter, we consider only mechanical waves, such as sound waves, water waves, and the waves transmitting in a guitar’s strings. • Elastic mediums are needed for the travel of mechanical waves. • Mechanical waves can appear when an initial disturbance is made to the mediums. On a microscopic level, the forces between atoms in the mediums are responsible for the propagation of the waves
The particles of the medium do not experience any net displacement in the direction of the wave-as the wave passes, the particles simply move back and forth through small distance about their equilibrium position What is a wave? It is the process of propagating oscillation in space What are transmitted by a wave? Energy, momentum, phase., but the particles are not
•The particles of the medium do not experience any net displacement in the direction of the wave-as the wave passes, the particles simply move back and forth through small distance about their equilibrium position. What is a wave? It is the process of propagating oscillation in space. What are transmitted by a wave? Energy, momentum, phase…, but the particles are not
.18-2 Types of waves Waves can be classified according to their properties as following 1.According to direction of particle motion (a)" Transverse waves(横波)”: If the motion of the particle is perpendicular to the direction of propagation of the waves itself (b)“ Longitudinal wave(纵波)”: f the motion of the particle e is parallel to the direction of propagation of the waves See动画库\波动与光学夹\2-01波的产生23
18-2 Types of waves Waves can be classified according to their properties as following. 1.According to direction of particle motion (a)“Transverse waves(横波)”: If the motion of the particle is perpendicular to the direction of propagation of the waves itself. (b)“Longitudinal wave(纵波)”: If the motion of the particle is parallel to the direction of propagation of the waves. See动画库\波动与光学夹\2-01波的产生 2 3
2. According to number of dimensions 1-D Waves moving along the string or spring 2-D Surface waves or ripple on water 3-D Waves traveling radially outward from a small source, such as sound waves and light waves 3 According to periodicity pulse waves or periodic wave The simplest periodic wave is a"simple harmonic wave" in which each particle undergoes simple harmonic motion
2. According to number of dimensions 1-D Waves moving along the string or spring 2-D Surface waves or ripple on water 3-D Waves traveling radially outward from a small source, such as sound waves and light waves. 3 According to periodicity pulse waves or periodic wave. The simplest periodic wave is a “simple harmonic wave’’ in which each particle undergoes simple harmonic motion