A boy yells in a narrow valley. the sound reflects off of a boulder that is 80 m away. how long will it take to hear the echo if the speed of a sound wave is 320 m/s? (speed = ) 0.25 seconds 0.50 seconds 2.0 seconds 4.0 seconds

Answers

Answer 1

Answer:

0.50 seconds

Step-by-step explanation:

The time it takes for an echo to return is the time it takes for the sound to make the round trip between the source and the reflecting object.

The boulder is 80 m away from the source, so the round-trip distance is 2×80 m = 160 m. At a speed of 320 m/s, it takes sound ...

(160 m)/(320 m/s) = 0.50 s

to make the round-trip.

It will take 0.50 seconds to hear the echo.

Answer 2

The time it will take to hear the echo, when the speed of a sound wave is 320 m/s is 0.50 seconds.

What is the speed of sound?

Speed of sound is the rate by which the sound wave travels. The speed of sound depends on the medium by which the sound wave is travelling.

The speed of the wave can be found out using the following formula.

[tex]s=\dfrac{d}{t}[/tex]

Here, (d) is the distance travelled by the wave and (t) is time taken by the wave to cover that distance.

A boy yells in a narrow valley. The sound reflects off of a boulder that is 80 m away.

For the echo, distance travelled will be doubled as it come back.Thus, the distance travelled by sound wave is,

[tex]d=2\times80\\d=160\rm\; m[/tex]

The speed of sound is 320 m/s. Put these value in the above formula as,

[tex]320=\dfrac{160}{t}\\t=0.5\rm\; s[/tex]

Thus, the time it will take to hear the echo, when the speed of a sound wave is 320 m/s is 0.50 seconds.

Learn more about the speed of sound here;

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Related Questions

The question is below:

Answers

QUESTION -> {WHICH EQUATION DESCRIBES A LINEAR FUNCTION }.

ANSWER :

B .

y =(1 — 6 ) ×

or.

C .

y = (2) ×

HOPE IT HELPS .

THANK ME LATER

THANKS.

What is the slope of a line that is perpendicular to line m ?

Answers

Answer:

b) -b/a

Step-by-step explanation:

Slopes of perpendicular lines are negative reciprocals. That means to flip the fraction and change the sign. :-)

Please Help! Will Give Brainlest! Locks In an Hour! Please try again if brainly Deletes your Answer!

Answers

Answer:

The answer to your question would be -0.383

Step-by-step explanation:

I have no idea why it's deleting my answers, but that's the best choice.

The wholesale price desk is $153 a certain furniture store marks up the wholesale price by 38% find the price of the desk in the furniture store . Found ur answer to the nearest cent

Answers

Answer:

Step-by-step explanation:

10% = 15.30

40%=61.20

1% = 1.53

2%=3.06

61.20+3.06=64.26

153+ 64.26=217.26

Mrs.martin's class has 8 boys out of a total of 20 students.which is the ratio of girls to boys in her class?

Answers

Answer:

8:20 or if you want it simplified 2:5

Step-by-step explanation:

if log7=a and log…
help me solve ths math problem on picture

Answers

[tex]\qquad\qquad\huge\underline{\boxed{\sf Answer☂}}[/tex]

Let's solve ~

[tex]\qquad \sf \dashrightarrow \: log_{4}(39.2) [/tex]

[tex]\qquad \sf \dashrightarrow \: log_{4}( {2}^{3} \times {7}^{2} \times 10 {}^{ - 1} ) [/tex]

[tex]\qquad \sf \dashrightarrow \: log_{4}( {2}^{3} ) + log_{4}( {7}^{2} ) + log_{4}(10 {}^{ - 1} ) [/tex]

[tex]\qquad \sf \dashrightarrow \: log_{ {2}^{2} }( {2}^{3} ) + log_{ {2}^{2} }( {7}^{2} ) + log_{ {2}^{2} }(10 {}^{ - 1} ) [/tex]

[tex]\qquad \sf \dashrightarrow \: \frac{3}{2} log_{2}(2) + \frac{2}{2} log_{2}(7) - \frac{1}{2} log_{2}(10) [/tex]

[tex]\qquad \sf \dashrightarrow \: \frac{3}{2} + a - \frac{b}{2} [/tex]

That's the required result ~

also you can take it's LCM and write it as :

[tex]\qquad \sf \dashrightarrow \: \dfrac{2a - b + 3}{2} [/tex]

What is the length of the sides of kite abcd? ab = 20; cd = 15 ab = 15; cd = 20 ab = 9; cd = 16 ab = 24; cd = 25

Answers

The length of the side AB and side CD of kite abcd which is shown in the figure is 15 units and 20 units respectively.

What is Pythagoras theorem?

Pythagoras theorem says that in a right angle triangle the square of hypotenuse side is equal to the sum of square of other two legs of right angle triangle.

Let the intersection point of dignoals is O. The figure of the kite ABCD, is attached below. The sides of the kite ABCD, are,

[tex]AO=12\\OB=9\\CO=12\\OD=16[/tex]

In the triangle AOB using the pythagours theorem,

[tex]AB=\sqrt{(AO)^2+(OB)^2}\\AB=\sqrt{(12)^2+(9)^2}\\AB=\sqrt{225}\\AB=15[/tex]

Similarly, in the triangle DOC using the pythagours theorem,

[tex]CD=\sqrt{(CO)^2+(OD)^2}\\CD=\sqrt{(12)^2+(16)^2}\\CD=\sqrt{400}\\CD=20[/tex]

Thus, the length of the side AB and side CD of kite abcd which is shown in the figure is 15 units and 20 units respectively.

Learn more about the Pythagoras theorem here;

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Answer:

its B

Step-by-step explanation:

(05.02)
A line passes through (2, 8) and (4, 12). Which equation best represents the line?
oy-x+6
=
2
y = 2x + 7
y = 2x + 4
oy-*x+10
=

Answers

Answer:

⊕ y=2x+4

Step-by-step explanation:

1) all the answers are provided in slope-interception form, then

2) the slope of the required line is: (12-8)/(4-2)=2. The required line is like to y=2x+??;

3) if the points (2;8) and (4;12) belong to the line required, then the point (0;4) also belongs to this one. It means, the interception is 4;

4) finally, the line required is y=2x+4.

PS. note, the suggested solution is not the only way.

Y^2+8y+2 y=-5 evaluate the expression

Answers

Answer:

the correct answer is shown below

Step-by-step explanation:

hope this helps

have an awesome day -TJ

pls mark brainliest if this helps :)

Use the explicit rule to find a12. an=-2n+8

Answers

The explicit rule formula an = -2n + 8 is an arithmetic progression

The value of a11 is -14

How to evaluate the explicit rule?

The explicit rule formula is given as:

an = -2n + 8

Substitute 11 for n to calculate a11

a11 = -2 * 11 + 8

Evaluate the product

a11 = -22 + 8

Evaluate the sum

a11 = -14

Hence, the value of a11 is -14

Answers

1 because if you were to get h rn e measure of the problem right here it would be a cosine of 1

Answer:

1 and 7

Step-by-step explanation:

let me know if this is helpful!

[tex]f(x) = 4x + 3[/tex]
[tex]g(x) = 5x - 4[/tex]
[tex]fg(x) = 20x + p[/tex]

Find the value of
[tex]p[/tex]

Answers

Let's see

[tex]\\ \rm\rightarrowtail (fog)(x)=f(g(x))[/tex]

[tex]\\ \rm\rightarrowtail f(5x-4)=20x+p[/tex]

[tex]\\ \rm\rightarrowtail 4(5x-4)+3=20x+p[/tex]

[tex]\\ \rm\rightarrowtail 20x-16+3=20x+p[/tex]

[tex]\\ \rm\rightarrowtail -13=p[/tex]

Answer:

[tex]\sf p = -13[/tex]

Step-by-step explanation:

Given functions:

[tex]\sf f(x)=4x+3[/tex]

[tex]\sf g(x)=5x-4[/tex]

[tex]\sf fg(x)=20x+p[/tex]

[tex]\sf fg(x)=f[g(x)][/tex]

This means g(x) is substituted for x in f(x).

[tex]\sf \implies f[g(x)]=4[g(x)]+3[/tex]

[tex]\sf =4(5x-4)+3[/tex]

[tex]\sf= 20x-16+3[/tex]

[tex]\sf =20x-13[/tex]

[tex]\sf f[g(x)]=f[g(x)][/tex]

[tex]\sf \implies 20x+p=20x-13[/tex]

[tex]\sf \implies p=-13[/tex]

Ann and Makiko like to swim laps at the community center pool.

They are swimming together today (day 1), but they are on different swim schedules. Ann swims every three days and Makiko swims every five days.

Question: How many times will they both swim at the pool on the same day
during the next ten weeks (including the first day)?

please explain process and show thinking in steps.

Answers

Answer: 5

=========================================================

Explanation:

The LCM of 3 and 5 is 3*5 = 15.

Every 15 days, the two people will swim together on the same day.

Day 1 = first day swimming togetherDay 1+15 = Day 16 = second day swimming togetherDay 16+15 = Day 31 = third day swimming together

And so on.

Keep this process going of adding on 15 to find this sequence

1, 16, 31, 46, 61, 76, ...

We stop the sequence once we either reach 70 or go over it because there are 7*10 = 70 days in ten weeks. This assumes we use a 7 day week rather than a 5 day week.

As shown in bold, there are 5 items smaller than 70. So the two people swam together a total of 5 times

-----------------

Alternatively, you can solve 15n+1 = 70 for n to get n = 4.6 which rounds down to n = 4 to represent the set {0,1,2,3,4} which has 5 items in it to represent the five times total they swim together.

n = 0 corresponds to day 15n+1 = 15(0)+1 = 1n = 1 corresponds to day 15n+1 = 15(1)+1 = 16

and so on until reaching n = 4 corresponding to day 15(4)+1 = 61.

Find the derivative of 30x² + 7x at x = 2.

Answers

Answer:

127

Step-by-step explanation:

Given :

30x² + 7x

On differentiating,

dy/dx = 2 * 30 * x²⁻¹ + 1 * 7 * x¹⁻¹dy/dx = 60x + 7

At x = 2

60(2) + 7120 + 7127

First differentiate

d/dx(x^n)=nx^n-1

[tex]\\ \rm\Rrightarrow \dfrac{d}{dx}(30x^2+7x)[/tex]

[tex]\\ \rm\Rrightarrow 60x+7[/tex]

Put x=2

60(2)+7120+7127

5. A triangle with a perimeter of
8 is dilated by a scale factor
of 2. What is the perimeter
of the new triangle?

Answers

Step-by-step explanation:

a scale factor normally applies to lengths (one-dimensional sizes).

the perimeter of a triangle is calculated only by using lengths, so we can apply the scaling factor directly to the perimeter.

perimeter of the new triangle = 2 × perimeter of the old triangle = 2×8 = 16

A bag contains 9 tiles, each with a different number from 1 to 9. You choose a tile without looking, put it aside, choose a second tile without looking, put it aside, then choose a third tile without looking. In how many different ways can you choose three tiles

Answers

Using the combination formula, it is found that there are 84 ways to choose the three tiles.

The order in which the tiles are chosen is not important, hence the combination formula is used to solve this question.

What is the combination formula?

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by:

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

In this problem, three tiles are chosen from a set of nine, hence:

[tex]C_{9,3} = \frac{9!}{3!6!} = 84[/tex]

There are 84 ways to choose the three tiles.

More can be learned about the combination formula at https://brainly.com/question/25821700

Describe the relationship between pi and circles.

Answers

Answer:

The circumference (C) of a circle is found by the equation C = 2*[tex]\pi[/tex]*radius

There is a second relationship between [tex]\pi[/tex] and circles. That of the area (A) of the circle which is found by the formula A = [tex]\pi*radius^{2}[/tex]

Step-by-step explanation:

Kaylib’s eye-level height is 48 ft above sea level, and addison’s eye-level height is 85 and one-third ft above sea level. how much farther can addison see to the horizon? use the formula d = startroot startfraction 3 h over 2 endfraction endroot, with d being the distance they can see in miles and h being their eye-level height in feet. startroot 2 endroot mi 2 startroot 2 endroot mi 14 startroot 2 endroot mi 28 startroot 2 endroot mi

Answers

The addison see to the horizon at 2 root 2mi.

We have given that,Kaylib’s eye-level height is 48 ft above sea level, and addison’s eye-level height is 85 and one-third ft above sea level.

We have to find the how much farther can addison see to the horizon

Which equation we get from the given condition?

[tex]d=\sqrt{\frac{3h}{2} }[/tex]

Where, we have

d- the distance they can see in thousands

h- their eye-level height in feet

For Kaylib

[tex]d=\sqrt{\frac{3\times 48}{2} }\\\\d=\sqrt{{3(24)} }\\\\\\d=\sqrt{72}\\\\d=\sqrt{36\times 2}\\\\\\d=6\sqrt{2}....(1)[/tex]

For Addison h=85(1/3)

[tex]d=\sqrt{\frac{3\times 85\frac{1}{3} }{2} }\\d\sqrt{\frac{256}{2} } \\d=\sqrt{128} \\d=8\sqrt{2} .....(2)[/tex]

Subtracting both distances we get

[tex]8\sqrt{2}-6\sqrt{2} =2\sqrt{2}[/tex]

Therefore, the addison see to the horizon at 2 root 2mi.

To learn more about the eye level visit:

https://brainly.com/question/1392973

Answer:

2 root 2mi.

Step-by-step explanation:

Edge2020

The interior angle of a regular polygon is 154°, What is
the size of an exterior angle?

Answers