{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

CHASE_HR17_ver1

# CHASE_HR17_ver1 - Chapter 17 Waves II The physics of sound...

This preview shows pages 1–9. Sign up to view the full content.

1 Chapter 17 The physics of sound waves is the basis of many fields of research, ranging from physiology, acoustic engineering, aviation, paleontology, military science and biology. In this chapter we introduce fundamental concepts and explore the properties of sound waves. Waves- II 17- 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
2 In this course, a sound wave is roughly defined as any longitudinal wave (particles moving along the direction of wave propagation). Sound Waves 17- Fig. 17-2 Wavefronts : surfaces over which the the oscillations due to the sound wave have the same value, e.g, at maximum crest. Rays : directed lines perpendicular to the wavefronts, indicate direction the direction of travel of the wavefronts Spherical waves Plane waves Particle motion
3 Speed of any mechanical wave depend on both Inertial properties of medium (to store kinetic energy) Elastic properties of medium (to store potential energy) The Speed of Sound 17- elastic property inertial property v τ μ = = In air (volume density) and (bulk modulus) B μ ρ τ change in pressure produces a fractional change in volume Material that is hard to compress large p B V V p V V B = - Speed of Sound: B v ρ =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4 Formal Derivation of the Speed of Sound Formula 17- x t v ∆ = Fig. 17-3 ( 29 (net force) F pA p p A pA = - + ∆ = -∆ (mass) m V A x Av t ρ ρ ρ = = = (acceleration) v a t = ( 29 v F ma pA Av t t ρ = → -∆ = 2 p v v v ρ = - and V A v t v V Av t V A v t V Av t v ∆ ∆ = = ∆ ∆ = = 2 p p B v B v v v V V ρ ρ = - = - = = Pulse travels right to left move with pulse. In frame of ref where Pulse is stationary the element moves to right
5 Demo 17.1: Lecture ( Beer ) Hall Longitudinal Wave 17- s x s t s=0 everywhere, equilibrium s(x,t=constant) s m s m s m s m s m s m s m Where is s max or min? Where is density max or min?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
6 Fig. 17-5 Traveling Sound Waves 17- Fig. 17-6 ( 29 m m p v s ρϖ =
7 Traveling Sound Waves, Part 2 17- ( 29 ( 29 Displaceme c nt: s , o m s x t s kx t ϖ = - Fig. 17-7 ( 29 ( 29 ( 29 Pressure Amplitu s n : i de , m m m p x t p kx t p v s ϖ ρϖ = ∆ - s=0 s=0 x =

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
8 17- Checkpoint 1 When the oscillating air element in Fig. 17- 7 a is moving rightward through point of zero displacement, is the pressure in the element (a) at its equilibrium value?
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern