A. Wave -A Disturbance Involving the Transfer of Energy from Place to Place

Waves 1. Characteristics of Waves a. Wave -a disturbance involving the transfer of energy from place to place b. Mechanical waves must travel through a material called a medium b.i. Gases like air b.ii. Liquids like water b.iii. Solids like rock c. Waves and Energy c.i. Mechanical waves form when a source of energy causes a medium to vibrate c.i.1. Vibration- repeated back and forth or up and down motion of a medium d. Types of Mechanical Waves d.i. Transverse waves- vibration occurs perpendicular to (at right angles to) the direction that the wave travels. d.i.1. Forms high and low points along a rope d.i.1.a. Crest-the top of the wave (high point) d.i.1.b. Trough-the bottom of the wave (low point)

d.ii. Longitudinal - vibrates the medium in the same direction that the wave travels. d.ii.1. Stretching a slinky out and watching the movement go back and forth. d.ii.1.a. Compression- the area of coils that move closer together as energy travels along the slinky d.ii.1.b. Rarefaction- the area of coils that are spread out before or after energy travels along the slinky. d.iii. Surface Waves- a combination of transverse and longitudinal waves. d.iii.1. The energy travels at right angles causing an up and down motion and a back and forth at the same time. d.iii.1.a. Causes particles to travel in a circular motion.

2. Properties of Waves a. Amplitude a.i. The maximum distance a medium vibrates from its resting position. The more energy a wave has, the higher its amplitude. The height of a wave’s crest depends on its amplitude a.ii. a.ii.1. Transverse waves-amplitude is the maximum distance the medium moves up or down from its resting position

a.ii.2. Longitudinal wave- amplitude is a measure of how compressed or rarefied the medium becomes a.ii.2.a. Very compressed=high amplitude

a.ii.3. Surface waves- amplitude depends on how far the water particles move above or below the surface when the water is calm a.ii.3.a. The more energy a wave has, the higher its amplitude a.ii.3.a.i. The height of a wave’s crest depends on its amplitude

b. Wavelength- b.i. Transverse wave- wavelength =the distance from crest to crest or trough to trough b.ii. Longitudinal wave-wavelength= the distance between compressions c. Frequency c.i. The number of waves that pass a given point in a certain amount of time c.i.1. Measured in hertz c.i.1.a. 1 wave per second 1/s = 1Hz c.i.1.b. 2 waves per second 2/s = 2Hz d. Speed d.i. How far the wave travels in a given amount of time d.i.1.a. ex 300 meters per second 300 m/s d.i.2. Different types of wave travel at different rates of speed d.i.2.a. Light is much faster than sound.

e. How are they all related? e.i. Speed = Wavelength x Frequency e.i.1. Rule applies as long as the temperature and pressure of the medium do not change. e.ii. Frequency = Speed/Wavelength e.iii. Wavelength = Speed/Frequency

3. Interactions of Waves a. What changes the direction of waves a.i. A;sldkfj a.ii. A;sodjf;as a.iii. A;odefj;aosdifj a.iv. a;osdefj;asdiof

b. Wave interference b.i. A;sldkjf b.i.1. ;alsdjkgf b.i.2. a;lsdkfjm b.ii. A;lsdkfj b.ii.1. al;sdkgfa;sdf b.iii. a;lskdf