Intro Question 1 A wave pulse is created by very sharply moving the free-end of a cord (or spring) to the side and back to its original position. How will the speed of this wave pulse be affected if you increase the tension on the cord (tighten it)? The speed will NOT be affected by the tension of the cord. The wave pulse will travel SLOWER in the tightened cord. The wave pulse will travel FASTER in the tightened cord Explain your choice:

Intro Question 2 A continuous wave is created by moving the end of a cord back and forth at a steady rate. If the distance the cord is displaced doubles (i.e. you move your hand back and forth twice as far) but the rate at which you create the wave remains constant, how will the speed of the wave be affected? The speed will NOT be affected by the amplitude of the cord. The wave pulse will travel HALF AS FAST when the amplitude is doubled. The wave pulse will travel TWICE AS FAST when the amplitude is doubled. The wave pulse will travel FASTER, but not necessarily twice as fast when the amplitude is doubled. The wave pulse will travel SLOWER, but not necessarily half as fast when the amplitude is doubled. Explain your Choice:

Introduction to Mechanical Waves Types of Waves and Wave Properties

Mechanical Waves What is a mechanical wave? A rhythmic disturbance that allows energy to be transferred through matter because of the motion of and interactions between the particles in the matter The Medium is the general term for the actual matter through which the wave is traveling. Wave Propagation is the term given when describing the transfer of energy through a medium

Direction of Particle motion Types of Waves Transverse Waves: A wave in which the energy is transferred in a direction perpendicular to the direction of particle movement This type of wave is typically only found in solids Example: Earthquake S - Waves, Guitar Strings Direction of wave propagation Direction of Particle motion

Transverse Wave Properties Amplitude (A): the maximum displacement of a particle in the medium from its rest position Trough: The point in a wave cycle where the medium has reached the maximum displacement BELOW the rest position Crest: The point in a wave cycle where the medium has reached the maximum displacement ABOVE the rest position Wavelength (λ): The distance from one point on a wave to the same point on the next wave (i.e. the distance from crest to crest)

Transverse Wave Properties Trough Crest (l)

Another Type of Wave Longitudinal or compression wave: A wave in which the energy is transferred in a direction parallel to the direction of particle movement Can be present in solids, liquids, or gases Example: Sound Waves, Earthquake P-Waves

Longitudinal Wave Properties Compression: The location in the medium of the greatest particle density and highest pressure Rarefaction: The location in the medium with the lowest particle density and lowest pressure Compression Rarefaction

Longitudinal Wave Properties The wavelength (λ) of a longitudinal wave is typically measured from the beginning of one compression to the beginning of the next (or center to center) Wavelength (λ)

Quantitative Wave Characteristics Wave Frequency ( f ): The number of complete wave cycles that pass by a point every second Units = Hertz (Hz) = 1 (1/sec) = 1 sec-1 Period (T): The amount of time that it takes for one complete wave cycle to pass by a point Units = Seconds (s) By definition, the frequency and the period of a wave are the inverse of each other: 𝒇= 𝟏 𝑻

𝑤𝑎𝑣𝑒 𝑠𝑝𝑒𝑒𝑑= 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝑝𝑒𝑟𝑖𝑜𝑑 Wave Speed Wave speed (v): Speed of a wave will be constant in a given medium Remember: 𝑣= 𝑑 𝑡 For waves: Distance (d) = wavelength (λ) Time (t) = period (T) 𝑤𝑎𝑣𝑒 𝑠𝑝𝑒𝑒𝑑= 𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ 𝑝𝑒𝑟𝑖𝑜𝑑 𝒗= 𝝀 𝑻 or 𝒗=𝒇∙𝝀