Concept explainers
Sounds are produced when vibrating objects create pressure waves in some medium such as air. When these variations in pressure reach the human eardrum, it causes the eardrum to vibrate in a similar manner and the ear detects sound. The intensity of sound is measured as power per unit area. The threshold for hearing (minimum sound detectable by a young, healthy ear) is defined to be I0 =10−12 W/m2 (watts per square meter). The sound level L, or “loudnessâ€� of sound, is measured in decibels (dB) as L=10log(II0), where I is the intensity of the given sound. Use this formula for Exercises 95-96.
a. Find the sound level of a jet plane taking off if its intensity is 1015 times the intensity of I0.
b. Find the sound level of the noise from city traffic if its intensity is 109 times I0.
c. How many times more intense is the sound of a jet plane taking off than noise from city traffic?

Want to see the full answer?
Check out a sample textbook solution
Chapter 3 Solutions
ALEKS 360 ACCESS F/PRECALCULUS...
Additional Math Textbook Solutions
Introductory Statistics
Thinking Mathematically (6th Edition)
A Problem Solving Approach To Mathematics For Elementary School Teachers (13th Edition)
Calculus: Early Transcendentals (2nd Edition)
Algebra and Trigonometry (6th Edition)
- The parametric equations of the function are given as x = 3cos 0 - sin³0 and y = 3sin 0 - cos³0. dy d2y Calculate and dx dx².arrow_forward(10 points) Let f(x, y, z) = ze²²+y². Let E = {(x, y, z) | x² + y² ≤ 4,2 ≤ z ≤ 3}. Calculate the integral f(x, y, z) dv. Earrow_forward(12 points) Let E={(x, y, z)|x²+ y² + z² ≤ 4, x, y, z > 0}. (a) (4 points) Describe the region E using spherical coordinates, that is, find p, 0, and such that (x, y, z) (psin cos 0, psin sin 0, p cos) € E. (b) (8 points) Calculate the integral E xyz dV using spherical coordinates.arrow_forward
- (10 points) Let f(x, y, z) = ze²²+y². Let E = {(x, y, z) | x² + y² ≤ 4,2 ≤ z < 3}. Calculate the integral y, f(x, y, z) dV.arrow_forward(14 points) Let f: R3 R and T: R3. →R³ be defined by f(x, y, z) = ln(x²+ y²+2²), T(p, 0,4)=(psin cos 0, psin sin, pcos). (a) (4 points) Write out the composition g(p, 0, 4) = (foT)(p,, ) explicitly. Then calculate the gradient Vg directly, i.e. without using the chain rule. (b) (4 points) Calculate the gradient Vf(x, y, z) where (x, y, z) = T(p, 0,4). (c) (6 points) Calculate the derivative matrix DT(p, 0, p). Then use the Chain Rule to calculate Vg(r,0,4).arrow_forward(10 points) Let S be the upper hemisphere of the unit sphere x² + y²+2² = 1. Let F(x, y, z) = (x, y, z). Calculate the surface integral J F F-dS. Sarrow_forward
- (8 points) Calculate the following line integrals. (a) (4 points) F Fds where F(x, y, z) = (x, y, xy) and c(t) = (cost, sint, t), tЄ [0,π] . (b) (4 points) F. Fds where F(x, y, z) = (√xy, e³, xz) where c(t) = (t², t², t), t = [0, 1] .arrow_forwardreview help please and thank you!arrow_forward(10 points) Let S be the surface that is part of the sphere x² + y²+z² = 4 lying below the plane 2√3 and above the plane z-v -√3. Calculate the surface area of S.arrow_forward
- (8 points) Let D = {(x, y) | 0 ≤ x² + y² ≤4}. Calculate == (x² + y²)³/2dA by making a change of variables to polar coordinates, i.e. x=rcos 0, y = r sin 0.arrow_forwardx² - y² (10 points) Let f(x,y): = (a) (6 points) For each vector u = (1, 2), calculate the directional derivative Duƒ(1,1). (b) (4 points) Determine all unit vectors u for which Duf(1, 1) = 0.arrow_forwardSolve : X + sin x = 0. By the false positioning numerical methodarrow_forward
- Algebra: Structure And Method, Book 1AlgebraISBN:9780395977224Author:Richard G. Brown, Mary P. Dolciani, Robert H. Sorgenfrey, William L. ColePublisher:McDougal Littell
- College AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage LearningCollege Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning





