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 I 0 = 10 − 12 W / m 2 (watts per square meter), The sound level L , or “loudness” of sound, is measured in decibels (dB) as L = 10 log ( I I 0 ) , where I is the intensity of the given sound. Use this formula for Exercises 95–96. a. Find the sound level of a motorcycle if its intensity is 10 10 times I 0 . b. Find the sound level of a vacuum cleaner if its intensity is 10 7 times I 0 . c. How many times more intense is the sound of a motoreycle than a vacuum cleaner?
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 I 0 = 10 − 12 W / m 2 (watts per square meter), The sound level L , or “loudness” of sound, is measured in decibels (dB) as L = 10 log ( I I 0 ) , where I is the intensity of the given sound. Use this formula for Exercises 95–96. a. Find the sound level of a motorcycle if its intensity is 10 10 times I 0 . b. Find the sound level of a vacuum cleaner if its intensity is 10 7 times I 0 . c. How many times more intense is the sound of a motoreycle than a vacuum cleaner?
Solution Summary: The author explains how to calculate the sound level of motorcycle if its intensity is 1010I_0.
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
I
0
=
10
−
12
W
/
m
2
(watts per square meter), The sound level L, or “loudness” of sound, is measured in decibels (dB) as
L
=
10
log
(
I
I
0
)
, where I is the intensity of the given sound. Use this formula for Exercises 95–96.
a. Find the sound level of a motorcycle if its intensity is
10
10
times
I
0
.
b. Find the sound level of a vacuum cleaner if its intensity is
10
7
times
I
0
.
c. How many times more intense is the sound of a motoreycle than a vacuum cleaner?
Jamal wants to save $48,000 for a down payment on a home. How much will he need to invest in an
account with 11.8% APR, compounding daily, in order to reach his goal in 10 years? Round to the
nearest dollar.
r
nt
Use the compound interest formula, A (t) = P(1 + 1)".
An account is opened with an intial deposit of $7,500 and earns 3.8% interest compounded semi-
annually. Round all answers to the nearest dollar.
a. What will the account be worth in 10 years? $
b. What if the interest were compounding monthly? $
c. What if the interest were compounded daily (assume 365 days in a year)? $
Kyoko has $10,000 that she wants to invest. Her bank has several accounts to choose from. Her goal is
to have $15,000 by the time she finishes graduate school in 7 years. To the nearest hundredth of a
percent, what should her minimum annual interest rate be in order to reach her goal assuming they
compound daily? (Hint: solve the compound interest formula for the intrerest rate. Also, assume there
are 365 days in a year)
%
Chapter 4 Solutions
Aleks 360 Access Card (18 Weeks) for College Algebra
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, algebra and related others by exploring similar questions and additional content below.
01 - What Is A Differential Equation in Calculus? Learn to Solve Ordinary Differential Equations.; Author: Math and Science;https://www.youtube.com/watch?v=K80YEHQpx9g;License: Standard YouTube License, CC-BY
Higher Order Differential Equation with constant coefficient (GATE) (Part 1) l GATE 2018; Author: GATE Lectures by Dishank;https://www.youtube.com/watch?v=ODxP7BbqAjA;License: Standard YouTube License, CC-BY