The loudness, L, measured in decibels (Db), of a sound intensity, I, measured in watts per square meter, is defined as L = 10 log StartFraction I Over I 0 EndFraction, where I 0 = 10 Superscript negative 12 and is the least intense sound a human ear can hear. Jessica is listening to soft music at a sound intensity level of 10^-9 on her computer while she does her homework. Braylee is completing her homework while listening to very loud music at a sound intensity level of 10^-3 on her headphones. How many times louder is Braylee’s music than Jessica’s?
Answers
Answer:
Braylee’s music is 3 times louder than Jessica's
Step-by-step explanation:
Given
[tex]L = 10\log\frac{I}{I_0}[/tex]
[tex]I_0 = 10^{-12}[/tex]
Required
Number of times Braylee's music is louder than Jessica's
First, we calculate the loudness of Jessica's music.
From the question;
[tex]I = 10^{-9}[/tex]
So, we have:
[tex]L = 10\log\frac{I}{I_0}[/tex]
[tex]L = 10\log\frac{10^{-9}}{10^{-12}}[/tex]
Apply law of indices
[tex]L = 10\log{10^{12-9}}[/tex]
[tex]L = 10\log{10^3[/tex]
Apply law of logarithm
[tex]L = 3*10\log{10[/tex]
[tex]\log10 = 1[/tex]
So:
[tex]L_1 = 3*10*1 = 30[/tex]
First, we calculate the loudness of Braylee's music.
From the question;
[tex]I = 10^{-3}[/tex]
So, we have:
[tex]L = 10\log\frac{I}{I_0}[/tex]
[tex]L = 10\log\frac{10^{-3}}{10^{-12}}[/tex]
Apply law of indices
[tex]L = 10\log{10^{12-3}}[/tex]
[tex]L = 10\log{10^9[/tex]
Apply law of logarithm
[tex]L = 9*10\log{10[/tex]
[tex]L_2 = 9*10*1 = 90[/tex]
At this point, we have:
[tex]L_1 = 30[/tex] --- Jessica's
[tex]L_2 = 90[/tex] --- Braylee's
Divide L2 by L1 to get the required number of times
[tex]n = \frac{L_2}{L_1}[/tex]
[tex]n = \frac{90}{30}[/tex]
[tex]n = 3[/tex]
Answer:
D.
Step-by-step explanation:
Related Questions
pleas help due tonight
Answers
Answer:
105.6 ft
Step-by-step explanation:
The perimeter of a shape is just the lengths of its sides added up. Since a square has 4 equal sides, and a side is 26.4, the answer is 26.4 * 4 = 105.6 ft
Add up all of the sides to get the perimeter.
26.4 + 26.4 + 26.4 + 26.4 = 105.6
123456762123456787654321`4567898 x 1
whats the answer
Answers
Answer:
123456762123456787654321`4567898
Answer:
123456762123456787654321`4567898
Step-by-step explanation:
how do i do this? please help with answer and explanation
Answers
Answer:
x=7
Step-by-step explanation:
180=25x+5
175=25x
7=x
Answer:
x = 7
Step-by-step explanation:
Now we have to,
→ Find the required value of x.
We know that,
→ Sum of all angles in a line is 180°.
Forming the equation,
→ (13x + 2) + (12x + 3) = 180°
Then the value of x will be,
→ (13x + 2) + (12x + 3) = 180°
→ 13x + 2 + 12x + 3 = 180°
→ (13x + 12x) + (2 + 3) = 180°
→ 25x + 5 = 180°
→ 25x = 180 - 5
→ 25x = 175
→ x = 175/25
→ [ x = 7 ]
Hence, the value of x is 7.
Write an inequality for the following.
Jackie spent no more than $40 on a video
Answers
Answer:
x ≥ $40
Step-by-step explanation:
Jackie didn't spend more than $40 on a video.
x ≥ $40
Find the value of x. Round to the
nearest tenth.
X
12
x = [?]
Answers
Answer:
63.4
Step-by-step explanation:
Tan = opposite/adjacent
Tan x = tan-1
Tan-1 (6/12)
=63.43494882
63.4
a. This dot plot shows the ages of students in a swimming class. How many students
are in the class?
Based on the dot plot, do you agree with each of the following statements? Explain
your reasoning.
b. The class is an adult swimming class.
C. Half of the students are between 2 and 3 years old.
Answers
Answer:16 students and C is right
Step-by-step explanation:
Add all the dots to get the number of students. C is correct because it is ages in months,not years.
Answer:
bbbbbb
Step-by-step explanation:
b ba bbssnbsn ss
Find the value of x.
10
53
HELP PLEASE!
Answers
Answer:
13.3
Step-by-step explanation:
By using sinus rule
if h= 19 inches, l= 27 inches, and w= 16 inches, what is the area of the figure shown above?
a. 299.5 square inches
b. 945 square inches
c. 665 square inches
d. 688.5 square inches
Answers
Answer:
That's easy! All you have to do is multiply the three numbers.
A = L * W * H
A = 25 * 14 * 19
A = 6650in²
Step-by-step explanation:If h = 19 inches, l = 25 inches, and w = 14 inches, what is the area of the figure shown above?
A.
587.5 square inches
B.
608 square inches
C.
825 square inches
D.
276.5 square inches
Find the length of the third side. If necessary, write in simplest radical form.
2V10
3
20 POINTS
Answers
Answer:
2V10 = 6.324 I have to write this
what are the X intercepts for y = 4sin2x
Answers
0 = 4sin(2x)
But I apologize I do not know how to calculate that so please look at the screenshot
who was correct and who was wrong?
Answers
Because according to PEMDAS, Parenthesis always start first
Solve the inequality for x. 3x + 9 < 3
Answers
Answer:
x > - 2
Step-by-step explanation:
3x + 9 < 3
3x (+ 9 - 9) < 3 - 9
3x < -6
3x/3 < -6/3
x > -2 (dividing by negative numbers, you reverse the inequality sign at the end of an equation)
FIND THE SIDES BRAINLIEST AND POINTS
Answers
Answer:
Look at the image.
Step-by-step explanation:
C = 2πr
2 · π · 5
≈ 31.42
31.42 ÷ 4 = 7.855
Drag the movable points to the correct position on the number line.
Answers
At a larger pizza party, there are 18 people. Each person wants 3 slices, and each pizza has 8 slices. How many pizzas should they order?
Answers
Answer:
7 pizzas
Step-by-step explanation:
18 people × 3 slices each = 54 slices
54 ÷ 8 = 6.75
7 pizzas
Answer:
They should order 7 pizzas.
Step-by-step explanation:
18 people x 3 slices per person = 54 slices you will need for everyone
54 slices divided by 8 = 6.75 pizzas.
Round 6.75 to 7 pizzas.
They should order 7 pizzas because you cannot ask the pizza place for 6.75 pizzas.
Using the list below, what is the ratio of goats to the total number of animals at the zoo? Animals at a Petting Zoo Chickens 2 Deer 4 Donkeys 3 Goats 6
Answers
Answer:
Ratio of goat to total number of animals at the zoo = 2 : 5
Step-by-step explanation:
Chickens = 2
Deer = 4
Donkeys = 3
Goats = 6
Total animals at the zoo = 15
what is the ratio of goats to the total number of animals at the zoo?
Ratio of goat to total number of animals at the zoo = 6 : 15
= 6/15
= 2/5
Ratio of goat to total number of animals at the zoo = 2 : 5
Someone please help will mark as brainliest
Answers
Answer:
c:88
Step-by-step explanation:
The angle that measures 92 degrees and the angle with the question mark are supplementary angles which mean their sums make up 180 degrees because they are on a line. So 180 degrees - 92 degrees = 88 degrees.
PLEASE HELP. ILL GIVE BRAINIEST (if i see links i get ur account banned)
Answers
Answer:
0, -2
Step-by-step explanation:
Can I have brainliest? I hope this helped and have a nice day!
Answer:
(-1, -5)
Step-by-step explanation:
hi im so sorry to bother you but can someone please help me with this please
I’ll give you the brainly if it’s correct im so sorry
Answers
Answer:
Question 1: ∠3 and ∠7 are corresponding angles.
Question 2: ∠2 and ∠8 are alternate interior angles.
Question 3: ∠4 and ∠6 are alternate exterior angles.
Question 4: ∠2 is congruent to ∠6.
Question 5: ∠8 is not congruent to ∠1.
Question 6: If ∠2 measures 132°, the measure of ∠7 would be 48°.
HELP ASAP, LINKS AND ABSURD ANSWERS WILL BE REPORTED! I WILL MARK BRAINLIEST!!
Answers
Answer:
6/10 or 3/5
Step-by-step explanation:
Evaluate by finding the value of x. 2/3x = 24
Answers
Answer:
x = 36
Step-by-step explanation:
This week is just one of the 40 weeks that you
spend in the classroom this school year. Convert
the fraction 1/40 to decimal form.
Answers
1/40 as a decimal is 0.025.
Plz help me giving brainliest
Answers
Answer:
B) this time im 90% sure
Step-by-step explanation:
Answer:
B - The interior angles of a quadrilateral add up to 360°
Step-by-step explanation:
A square is a Quadrilateral and when you add up
90+90+90+90
you get...
360
Kim is competing in a 40-mile bicycle race. She has completed 65% of the race. How many miles does Kim have left to cycle? A. 12 miles B. 14 miles C. 26 miles D. 28 miles
Answers
She completed 65% so she has 35% more to go. ( 100% - 65% = 35%)
Multiply the length of the race by the percentage left:
40 x 0.35 = 14
She has 14 miles left.
The answer is B. 14 miles
HELP PLEASE!! BRAINLIST IF CORRECT
adriana thinks the measure of angle CBE is 70 degrees.
Lila thinks the measure is 68 degrees.
Who is correct?
Adriana
Lila
Explain your thinking
BRAINLIST if correct
Answers
Answer:
Adriana is correct
Step-by-step explanation:
if you get rid of E, it is a 90 degree angle. so:
90-20=70
which is Adriana's answer
HELP ILL GIVE BRAINLIEST
Answers
Answer:
0.29
Step-by-step explanation:
14/25 * 4 = 56/100
|
\ /
56
56 + 15 = 71
100 - 71 = 29
29% = 0.29
Giving brainliest for correct answer!
Answers
Answer:
10 7
20 14
30 21
Step-by-step explanation:
can someone help me find the slope . and tell me how you got the steps and answer. question-What is the slope of the line that passes through the points (-4, -8) and (-10, 8)?
Answers
Answer:
m = -8/3
Step-by-step explanation:
Keep in mind that slope is defined as m = rise / run, or, alternatively,
m = (change in y ) / (change in x).
If we start at (-10, 8) and move to (-4, -8),
the x coordinate is seen to increase by 6 from -10 to -4, and
the y coordinate decrease by 16 from 8 to -8.
Thus, the slope of the line segment connecting these two points is
m = -16 / 6, or m = - 8/3
It seems simple but I need help
Answers
Answer:
[tex]\huge\boxed{Answer\hookleftarrow}[/tex]
[tex]( \frac{2}{5} ) {}^{2} \\ = \frac{2 {}^{2} }{5 {}^{2} } \\ = \frac{4}{25} \\ = 0.16 [/tex]
➟ The answer = 4/25 in fraction form or 0.16 in standard form.
# ꧁❣ RainbowSalt2²2² ࿐
f(x) = 2x^2
Find f(-3)
Answers
Answer:
36
Step-by-step explanation:
f(x)=2x^2
f(-3)=2(-3)^2
f(-3)= -6^2
f(-3)=36
Answer:
Step-by-step explanation:
f(x) = 2 x^2
f(-3) means that wherever there is an x on the right, put in - 3
f(-3) = 2 (-3)^2
(-3)^2 = 9
f(-3) = 2 * 9
f(-3) = 18