47.Explain sound needs a medium for propagation​

Answers

Answer 1

Answer:

Sound needs a material medium for their propagation like solid, liquid or gas to travel because the molecules of solid, liquid and gases carry sound waves from one point to another. Sound cannot progress through the vacuum because the vacuum has no molecules which can vibrate and carry the sound waves.


Related Questions

please help me i really need help please

Answers

Answer:

39°

Step-by-step explanation:

180-90-51=39

Answer:

its 39

Step-by-step explanation:

you know that a right triangle already has the angle 90 so 51 plus 90 equals 141

180-141=39

Luis walked for 16 minutes. Natalie walked for w minutes. Luis walked twice as long as Natalie. How long did Natalie walk?

Answers

Answer:

Natalie walked for 4 minutes because 16 divided by 2 is 4

Answer:

8

Step-by-step explanation:

16/2=8

8increase by 3 times a number (t).

Answers

Answer:

8 + 3n

Step-by-step explanation:

Answer:

8 + 3t

Explanation:

Gravel is being dumped from a conveyor belt at a rate of 15 ft3/hr and its coarseness is such that it forms a pile in the shape of an inverted right cone whose height is three times its base radius. How fast is the height of the pile increasing when the pile has a height of 10 ft

Answers

Answer:

0.43 ft/hr

Step-by-step explanation:

dv/dt = 15ft³/hr

Height = 10ft

We are required to get dh/dt

h = 3r

r = h/3

Formula for volume = 1/3πr²h

We put value of h

1/3π(h/3)²h

= 1/3π(h²/9)h

= 1/3πh³/9

= πh³/29

dv/dt = 1/27π.3h²dh/dt

= dv/dt = πh²/9dh/dt

Remember dv/dt = 15

When we put this in we get

dh/dt = 15x9/3.142x10²

= 135/314.2

= 0.43 ft³/hr

Please check the attachment I added also to add you.

10. Find the volume of the prism.
3 ft
7 ft
2 ft

Answers

Three times two is 6, times 7 is 42. That’s the answer.

Please help will give brainliest

Answers

Answer:

25 is the area because5 times 5 equals 25

Step-by-step explanation:

hope this helps

Answer:

25

Step-by-step explanation:

Help please thank uuuu

Answers

Answer:

B. x = 7; AB = 9, AC = 12

Step-by-step explanation:

12/4 = (x + 2)/(x - 4) (similar triangles theorem)

3 = (x + 2)/(x - 4)

Cross multiply

3(x - 4) = (x + 2)

3x - 12 = x + 2

Collect like terms

3x - x = 12 + 2

2x = 14

x = 14/2

x = 7

✔️AB = x + 2 = 7 + 2

AB = 9

✔️AC = (x + 2) + (x - 4) = (7 + 2) + (7 - 4)

AC = 9 + 3

AC = 12

A piece of wood is 3 1/2 feet long how many total inches long is it?

Answers

Answer:

42 inches

Step-by-step explanation:

1 foot is 12 inches

12 times 3=36

12 divided by 2=6

36+6=42

giving brainliest *easy*

Answers

Answer:

pi

Step-by-step explanation:

to convert angles to radians you must multiply the angle measurement by the formula pi/180

180 x pi/180

the 180s cancel out and you are left with pi

Answer:

3.14159 Radian

Step-by-step explanation:

3.142rad × 180/π = 180°

Find the errors and correct the following mathematical sentences.​

Answers

Answer:

Step-by-step explanation:

18). 3x + 2 ÷ 3x = [tex]\frac{2}{3x}[/tex]

     Since, 3x + 2 ÷ 3x = 3x + [tex]\frac{2}{3x}[/tex]

      Therefore, right hand side of the equation will be = 3x + [tex]\frac{2}{3x}[/tex]

20). [tex]\frac{4x+3}{3}=x+1[/tex]

       Since, [tex]\frac{4x+3}{3}=\frac{4x}{3}+\frac{3}{3}[/tex]

                            = [tex]\frac{4}{3}x+1[/tex]

Therefore, right hand side of the equation should be [tex]\frac{4}{3}x+1[/tex].

PLEASE HELP ASAP
TRIGONOMETRY

Answers

Answer:

11). x = 25.8°

12). x = 67.3°

Step-by-step explanation:

11). By using sine rule in the given triangle,

   cos(x) = [tex]\frac{\text{Adjacent side}}{\text{Hypotenuse}}[/tex]

   cos(x) = [tex]\frac{27}{30}[/tex]

   x = [tex]\text{cos}^{-1}(\frac{9}{10} )[/tex]

   x = 25.84

   x ≈ 25.8°

12). By applying tangent rule in the given triangle,

    tan(x) = [tex]\frac{\text{Opposite side}}{\text{Adjacent side}}[/tex]

    tan(x) = [tex]\frac{43}{18}[/tex]

    x = [tex]\text{tan}^{-1}(\frac{43}{18} )[/tex]

    x = 67.29°

    x ≈ 67.3°  

in the coordinate plain the point located at (-3,4) was reflected and is now located at (3,4). how was the point reflected

Answers

Answer:

they reflect thru the y-axis

Step-by-step explanation:

A computer program found that the line c=2t−89c=2t−89c=2t−89 is a good fit for the data. Use this equation to predict how many cups of lemonade Lin might sell on a day when the high temperature is 74 degrees.

Answers

Answer:

58cups

Step-by-step explanation:

Given the equation for the line as c = 2t - 89

If the temperature is 74 degrees, then we can find the number of cups at this temperature;

Substitute t = 74 unti the expression

x = 2(74) - 89

c = 147 - 89

c = 58cups

Hence the number of cups of lemonade is 58cups

What is x in 1/150/1/200x2=x

Answers

Answer:

6.66666667E-5

hope this helped a bit!

Help please!!!
I’m failing math and I need help

Answers

Answer:

3.

vertically opposite angles ,

= 30°

4. 50° +30°+2x = 180°

80°+2x=180°

2x=180°-80°

2x=100°

Pls help

Find the surface area of the composite figure.

Answers

Answer:

644 cm³

Step-by-step explanation:

Surface area of the composite figure = (surface area of the upper cuboid - base area of upper cuboid) + (surface area of the lower cuboid - base area of the upper cuboid)

✔️Surface area of upper cuboid = 2(LW + LH + WH)

L = 3

W = 3

H = 8

Surface area of upper cuboid = 2(3*3 + 3*8 + 3*8) = 2(9 + 24 + 24) = 114 cm²

✔️Surface area of Surface area of lower cuboid = 2(LW + LH + WH)

L = 12

W = 10

H = 7

Surface area of lower cuboid = 2(12*10 + 12*7 + 10*7) = 2(120 + 84 + 70) = 548 cm²

✔️Base area of upper cuboid = L*W

L = 3

W = 3

Base area = 3*3 = 9 cm²

✅Surface area of the composite figure = (114 - 9) + (548 - 9) = 105 + 539 = 644 cm³

Triangle PQR IS SIMILAR TO Triangle KLM.

What is the value of x in inches?

A 7 in.
B 148 in.
C 92 in.
D 168 in.

Answers

D. 168 in.

15/72 = 35/168

Identify each part in the expression below. will give brainliest

Answers

Answer:

smalls

Step-by-step explanation:

I need help on this question someone please help. x/4=-12 (this says x divided by 2 equals -8). Explain how you would solve for x and what you would get. I’m in 7th grade so can someone make it easy to read like at the explaining part thanks.

Answers

So since our first example is X/4=-12 the first step would be to multiply 4 to both sides meaning you would multiply 4 by the division of 4 so it cancels out because they’re opposite operations do the same to the -12, so -12x4=-36 x=-36 the other example would be the same multiply 2 to both sides so on the left it would cancel out and on the right it would be -16 which is the answer to x
Hope this could help at least a little

Which expression correctly represents 10 times the difference of a number and six

Answers

Answer:

10(6 - x) or 10(x - 6)

Step-by-step explanation:

Let the number be x.

Answer: 10(6 - x) or 10(x - 6)

Part B: Which box-and-whisker plot displays
Mario's data?


Brainliest quick

Answers

Answer:

Step-by-step explanation:

i think it's D i have the same test today

Answer:

C cause it has to be 54 then the median is 58

Step-by-step explanation:

jessica wondered if elementary school students tend to write more when they are given

Answers

full question plsAnswer:

Step-by-step explanation:

HHHEEELLLPPPPP MMMMMMEEEEEE!!!!!!

Which is the graph of the function g(x)=−x^2−4x−1?

Answers

Answer:

its a, the first one

Step-by-step explanation:

i graphed it have a good day (:

What is the area of this figure?

Enter your answer in the box.

___in^2

Answers

Answer:

400

Step-by-step explanation:

8*20/2+16*20=400.

2) The number of rose blooms in Betty's garden is 24 more than the number of blooms in May's garden. There
are at least 135 rose blooms in Betty's garden. How many blooms are possible in May’s garden?

Answers

Answer:

There are at least 111 rose blooms in May's Garden.

Step-by-step explanation:

135-24 is 111 and Betty doesn't have a maximum of rose blooms so that means she can have an infinite amount but it also means that may can't have less than 111.

Please let me know if I am incorrect

Find the identical expression for the following plz show work

Answers

THAT IS A VIRUS DO NOT GO TO IT DONT GO TO ANY LINK THEY ALL ARD VIRUSES

Write the ratios of each for the given triangle below
SinA=
CosA=
TanA=
SinB=
CosB=
TanB=

Answers

Answer:

i have made it in above picture

What is 2 ½ divided by ½ equal too

Answers

Answer:

it woulb be 1.25

Ignore the answer I chose it didn't let me click off of it

Answers

Answer:

d i think

Step-by-step explanation:

pretty sure it would be d

Clara went to a music store and brought some CDs and DVDs. She paid $14 for each CD and $17 for each DVD. Let x represent the number of CDs that she purchased and y represent the number of DVDs.

Answers

14x+17y= total spent
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