### Create a StudySoup account

#### Be part of our community, it's free to join!

Already have a StudySoup account? Login here

# General Physics II PHYS 408

UNH

GPA 3.64

### View Full Document

## 21

## 0

## Popular in Course

## Popular in Physics 2

This 3 page Class Notes was uploaded by Cayla Kilback on Thursday October 29, 2015. The Class Notes belongs to PHYS 408 at University of New Hampshire taught by Staff in Fall. Since its upload, it has received 21 views. For similar materials see /class/231704/phys-408-university-of-new-hampshire in Physics 2 at University of New Hampshire.

## Reviews for General Physics II

### What is Karma?

#### Karma is the currency of StudySoup.

#### You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!

Date Created: 10/29/15

Lecture 5 Sound Waves Part I Chapter 18 14 Clari cation First something that it seems was not entirely clear from either the book or my lectures so far The question is deceiVingly simple What is the Amplitude of a wave If I give you the equation y f x ym sin 06 at dz you would know immediately to take the blue partym That is correct But what about yt x 6ym sin kx at 96 The answer is now 6 ym because the amplitude of a wave is the term that multiplies the oscillating term For a standing wave it gets even trickier because there are 2 oscillating terms one with respect to x and one with respect to I So it depends on the details of the question what the oscillating term is Let s take an example y xt4ym cosmt sinkx 11 If the question is What is the amplitude of this standing wave We mean what is the maximum of the wave for any x and any I The answer is 4 ym If the question is What is the amplitude of this standing wave at x The answer is 4ym sin2 4 I used k 2 13 1312003 Traveling Sound Waves In a traveling sound wave the particles of air move back and forth along the path of motion This movement is really very small compared to the wavelength We can write the displacement of the particles with respect to their equilibrium point as sxtsm coskx at 12 For such a wave for any wave really the wave properties k A a f T all have the same meaning as for a transverse wave When particles are displaced they must cause pressure differences The book on pages 403 and 404 shows how you derive the change in pressure from the displacement I won t repeat it here but it is a good derivation and you should know how it works They find ApxtApm sinkx at 13 and relate Apm to Sm with the equation Apm vasm Bk sm 14 The graph for such a wave looks like the Sound Wave relating SAp one here on the right Spat um Note that as the displacement goes through the equilibrium point the pressure is either at a maximum or a minimum This seems counter intuitive How do we explain it Think of the particles themselves Take the point at X30cm The particles just to the left of this point Xlt30cm have negative App displacement so they are a little bit further Pa away than usual The ones on the right Xgt30cm have a positive displacement they are also further away than usual So the pressure at X3OCII1 is at it s lowest X cm 23 1312003 Interference of Sound Waves Sound waves interfere just like 39 transverse waves do The resulting C wave displacement pressure is the 39 sum of the two or more waves you started with If you have two point sound sources SI and 1 a distance d apart emitting M the same sound frequency and Q phase these waves will interfere The pattern of interference can be calculated See the demo in Toys How is that done The phase difference of the waves at point P is given directly from the difference in path length AL L2 we find AL 27Z 7 Fully constructive interference happens when 7127239 so AL 0123 2 Fully destructive interference happens when 271 l 7239 so 2 051 52535 2 The trick is to find the AL term 2 A x2 y gt 2 L2 x2 lty gt 33 1312003 15 16 17 18

### BOOM! Enjoy Your Free Notes!

We've added these Notes to your profile, click here to view them now.

### You're already Subscribed!

Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'

## Why people love StudySoup

#### "Knowing I can count on the Elite Notetaker in my class allows me to focus on what the professor is saying instead of just scribbling notes the whole time and falling behind."

#### "When you're taking detailed notes and trying to help everyone else out in the class, it really helps you learn and understand the material...plus I made $280 on my first study guide!"

#### "I was shooting for a perfect 4.0 GPA this semester. Having StudySoup as a study aid was critical to helping me achieve my goal...and I nailed it!"

#### "It's a great way for students to improve their educational experience and it seemed like a product that everybody wants, so all the people participating are winning."

### Refund Policy

#### STUDYSOUP CANCELLATION POLICY

All subscriptions to StudySoup are paid in full at the time of subscribing. To change your credit card information or to cancel your subscription, go to "Edit Settings". All credit card information will be available there. If you should decide to cancel your subscription, it will continue to be valid until the next payment period, as all payments for the current period were made in advance. For special circumstances, please email support@studysoup.com

#### STUDYSOUP REFUND POLICY

StudySoup has more than 1 million course-specific study resources to help students study smarter. If you’re having trouble finding what you’re looking for, our customer support team can help you find what you need! Feel free to contact them here: support@studysoup.com

Recurring Subscriptions: If you have canceled your recurring subscription on the day of renewal and have not downloaded any documents, you may request a refund by submitting an email to support@studysoup.com

Satisfaction Guarantee: If you’re not satisfied with your subscription, you can contact us for further help. Contact must be made within 3 business days of your subscription purchase and your refund request will be subject for review.

Please Note: Refunds can never be provided more than 30 days after the initial purchase date regardless of your activity on the site.