A stereo speaker is placed between two observers who are 35 m apart, along the line connecting them. If one observer records an intensity level of 64 dB, and the other records an intensity level of 85 dB, how far is the speaker from each observer

Answers

Answer 1

Answer:

   x = 2,864 m ,       Ra = 32.1 m                       

Explanation:

Let's solve this problem in parts, let's start by finding the intensity of the sound in each observer

observer A β = 64 db

             β = 10 log Iₐ / I₀

where I₀ = 1 10⁻¹² W / m²

              Iₐ = I₀ 10 (β/ 10)

let's calculate

              Iₐ = 1 10⁻¹² (64/10)

              Iₐ = 2.51 10⁻⁶ W / m²

Observer B β = 85 db

             I_b = 1 10-12 10 (85/10)

             I_b = 3.16 10⁻⁴ W / m²

now we use that the emitted power that is constant is the intensity over the area of ​​the sphere where the sound is distributed

              P = I A

therefore for the two observers

              P = Ia Aa = Ib Ab

the area of ​​a sphere is

               A = 4π R²

we substitute

               Ia 4pi Ra2 = Ib 4pi Rb2

               Ia Ra2 = Ib Rb2

Let us call the distance from the observer be to the haughty R = ax, so the distance from the observer A to the haughty is R = 35 ax; we substitute

             Ia (35 -x) 2 = Ib x2

we develop and solve

           35-x = Ra (Ib / Ia) x

           35 = [Ra (Ib / Ia) +1] x

           x (11.22 +1) = 35

           x = 35 / 12.22

            x = 2,864 m

This is the distance of observer B

The distance from observer A

            Ra = 35 - x

            Ra = 35 - 2,864

            Ra = 32.1 m


Related Questions

A 7.50 kg bowling ball has 70.4
kg•m/s of momentum. What is its
velocity?

Answers

Answer:

9.39 m/s

Explanation:

The velocity of the bowling ball can be found by using the formula

[tex]v = \frac{p}{m} \\ [/tex]

p is the momentum

m is the mass

From the question we have

[tex]v = \frac{70.4}{7.5} \\ = 9.38666666..[/tex]

We have the final answer as

9.39 m/s

Hope this helps you

''The Evolution Of Sakura And Hinata''

Who looks better?! Who do you think has improved a lot in the Naruto Series?

Answers

Answer:

hinata

Explanation:

unlike sakura she has not change at all

In my opinion, Sakura looks prettier and she developed way more than Hinata. Personally, I dislike the both of them because of their Tsundere side, but there's no doubt Sakura developed way more than Hinata. In the original Naruto series, Sakura was honestly a burden. There were some missions where Team 7 had to rescue Sakura. However, after the training with Tsunade, she gained monster strength and healing abilities. Additionally, throughout Naruto Shippuden she learned new jutsu like Yin Seal: Release.    

     However with Hinata, it's a bit more different. In the original Naruto series, I feel believe she was stronger than Sakura. She relied on her infamous visual prowess--the Byakugan. However in Naruto Shippuden, she improved slightly compared to Sakura. In my opinion, she would have been the most useless shinobi out of the eleven characters (YES, more useless than Tenten) if it weren't for her visual prowess. She's fortunate that she was born into the Hyuga clan. Every jutsu that's in her arsenal relies heavily on the Byakugan. And if Sakura and Hinata were to battle each other, it's most likely that Sakura would win. It's true that Hinata can block Sakura's chakra points, but I think she could dodge her attacks. And even if her chakra points are blocked, Sakura can rely on Taijutsu and raw strength to win.

Though both kunoichi are honorable, I believe Sakura is more prettier and stronger than Hinata.

When a mass of a cart is 10 kg, and an applied force is 5 N, The acceleration of the cart is

5.0 m/s2
2.0 m/s2
0.5 m/s2
0.2 m/s2

Answers

Answer:

0.5 m/s2

Explanation:

F = ma

5 = 10a

a = 5/10

a =0.5


9. In the graph below, what is the force being exerted on
the 16-kg cart?
A. 4N
C. 16N
B. 8N
D. 32 N

Answers

Answer:

D

Explanation:

15 points.

An object of mass 100 kg is observed to accelerate at a rate of 15
m/s/s. Calculate the force required to produce this acceleration.

Answers

Answer:

its 0.5 for all i beleive

Explanation:

How do unbalanced forces acting on an object affect its motion when the object is at rest? What if it is moving?

Answers

Answer:

It pushes it because an unbalanced force is pushing more newtons than something that isn't even moving. Even if it is moving, it depends which side is pushing/pulling the most force.

Explanation:

Answer:

It pushes it because an unbalanced force is pushing more newtons than something that isn't even moving. Even if it is moving, it depends which side is pushing/pulling the most force.

A 40-cm-diameter, 300 g beach ball is dropped with a 4.0 mg ant riding on the top. The ball experiences air resistance, but the ant does not. What is the magnitude of the normal force exerted on the ant when the ball's speed is 4.0 m/s?

Answers

Answer:

The normal force exerted on the ant is 0.75 N.

Explanation:

Given;

diameter of the ball, D = 40 cm = 0.4m

radius of the ball, r = 0.2m

mass of the beach ball, m₁ = 300 g = 0.3 kg

mass of the ant, m₂ = 4 x 10⁻⁶ kg

speed of the ball, v = 4 m/s

The area of the ball, assuming spherical ball is given by;

A = 4πr²

A = 4π(0.2)² = 0.5027 m²

The drag force (resistance) experienced by the spherical ball is given as;

[tex]F_D = \frac{1}{2}C\rho Av^2[/tex]

where;

C is the drag coefficient of the spherical ball = 0.45

ρ is density of air = 1.21 kg/m³

[tex]F_D = \frac{1}{2}C\rho Av^2\\\\F_D = \frac{1}{2}(0.45)(1.21) (0.5027)(4)^2\\\\F_D = 2.19 \ N[/tex]

The downward force of the ball due to its weight and that of the ant is given by;

[tex]F_g = mg\\\\F_g =g(m_{ant} + m_{ball})\\\\F_g = g(4*10^{-6} \ kg\ + \ 0.3\ kg)\\\\F_g = g(0.300004 \ kg) \ \ \ (mass \ of \ the \ ant \ is \ insignificant)\\\\F_g = 9.8(0.3)\\\\F_g = 2.94 \ N[/tex]

The net downward force experienced by the ball is given by;

[tex]F_{net} = F_g - F_D\\\\F_{net} = 2.94 \ N - 2.19 \ N\\\\F_{net} = 0.75 \ N[/tex]

This downward force experienced by the ball is equal to the normal reaction it exerts on the ant.

Thus, the normal force exerted on the ant is 0.75 N.

What is the average power consumption in watts of an appliance that uses 4.69 kW · h of energy per day?

Answers

Answer:

The average power is  [tex]P = 195 .42 \ W[/tex]

Explanation:

From the question we are told that

   The  energy of the appliance is  [tex]E = 4.69 \ kWh = 4.69 *10^{3} \ \ Wh[/tex]

    The time considered is   [tex]t = 1 \ day = 24 \ hours[/tex]

Generally the average power consumption is mathematically represented as

      [tex]P = \frac{E}{t}[/tex]

=>   [tex]P = \frac{4.69 *10^{3}}{24 }[/tex]

=>   [tex]P = 195 .42 \ W[/tex]

In the concluding paragraph, how does the author make the conflicting point of view that vegetarianism is strange and unnatural seem less reasonable?

Answers

Answer:

By pointing out that vegetarianism isn't contagious

Explanation:

I got this right on iready!

Answer:

by point out how food isn't contagious

Explanation:

got it right

How does cycling of matter occur in Earth’s mantle?

A. Hot, soft rock rises from the bottom of the mantle toward the top, cools, and sinks back through the mantle.

B. Hot, soft rock sinks to the mantle, cools, and rises to Earth’s crust.

C. Solid rock rises from the bottom of the mantle, cools, and sinks back through the mantle.

D. Solid rock sinks to Earth’s core and then rises to form lava.



i need help fast plz and thank you
11/24/2020

Answers

Answer:  

Correct answer to this is: A

Hopefully, this helped out a bit :)  

A runner taking part in the 200 m dash must run around the end of a track that has a circular arc with a radius of curvature of 50 m. If he completes the 200 m dash in 29.6 s and runs at constant speed throughout the race, what is the magnitude of his centripetal acceleration (in m/s2) as he runs the curved portion of the track?

Answers

Answer:

The centripetal acceleration of the runner as he runs the curved portion of the track is 0.91 m/s²

Explanation:

Given;

distance traveled in the given time = 200 m

time to cover the distance, t = 29.6 s

speed of the runner, v = d / t

v = 200 / 29.6

v = 6.757 m/s

The centripetal acceleration of the runner is given by;

[tex]a_c = \frac{V^2}{r}[/tex]

where;

r is the radius of the circular arc, given as 50 m

Substitute the givens;

[tex]a_c = \frac{V^2}{r}\\\\a_c = \frac{(6.757)^2}{50}\\\\a_c = 0.91 \ m/s^2[/tex]

Therefore, the centripetal acceleration of the runner as he runs the curved portion of the track is 0.91 m/s².

A rack of seven spherical bolwing balls (each 7.00 kg, radius of 9.50 cm) is positioned along a line located a distance =0.850 m from a point ,

Calculate the gravitational force
the bowling balls exert on a ping-pong ball of mass 2.70 g, centered at point .

Answers

Answer:

8.72*[tex]10^{-12}[/tex] N

Explanation:

force of attraction f = G m1m2/ r^2 = [tex]\frac{6.67*10^{-11}*7*5*2.70 }{.85*.85*1000}[/tex] = 8.72*[tex]10^{-12}[/tex] N

The gravitational force the bowling balls exert on a ping-pong is given as  8.72*[tex]10^{-12}[/tex] N.

What is force?

A force is an effect that can alter an object's motion according to physics. An object with mass can change its velocity, or accelerate, as a result of a force. An obvious way to describe force is as a push or a pull. A force is a vector quantity since it has both magnitude and direction.

force of attraction

f = G [tex]m_1m_2[/tex]/r²

 = [tex]6.67*10^{-11}[/tex]*7*5*2.70/.85²*1000

 = 8.72*[tex]10^{-12}[/tex] N

The gravitational force the bowling balls exert on a ping-pong is given as  8.72*[tex]10^{-12}[/tex] N.

To learn more about force refer to the link:

brainly.com/question/13191643

#SPJ3

Mr. Jones starts from rest and begins to accelerate straight to the bathroom at a rate of 0.5 m/s for 10 seconds. What kind of motion is this
A. linear
b centripetal
c.free fall
d projectile​

Answers

Answer:

A. linear

Explanation:

because they are going in a straight line

Which of the following is NOT a type of variable?

A. Burette
B. Ordered
C. Continuous
D. Categoric

Answers

Answer:

A

Explanation:

because its not trust me :)

Can someone help me with this question

Answers

Answer:

Net force: 20 N to the right

mass of the bag: 20.489 kg

acceleration:  0.976  m/s^2

Explanation:

Since the normal force and the weight are equal in magnitude but opposite in direction, they add up to zero in the vertical direction. In the horizontal direction, the 195 N tension to the right minus the 175 force of friction to the left render a net force towards the right of magnitude:

195 N - 175 N = 20 N

So net force on the bag is 20 N to the right.

The mass of the bag can be found using the value of the weight force: 201 N:

mass = Weight/g = 201 / 9.81 = 20.489 kg

and the acceleration of the bag can be found as the net force divided by the mass we just found:

acceleration = 20 N / 20.489 kg = 0.976  m/s^2

Discuss two ways to determine your muscular strength explain the advantages

Answers

Answer:

Two ways to determine ones muscular strength is to either lift the heaviest weight possible or by doing one repetition. The advantages these two methods is that it is easy to determine and does not require calculations or estimating.

Explanation:

Answer:

Two ways to determine ones muscular strength is to either lift the heaviest weight possible or by doing one repetition. The advantages these two methods is that it is easy to determine and does not require calculations or estimating.

Explanation:

is 2/2 1 or 0? please help lol

Answers

Answer:

1.

Explanation:

Hello!

In this case, for such mathematical operations, we can wee that the slash represents a fraction or a division, say 8 ÷ 4 = 2, 6 ÷ 3 = 2, 20 ÷ 4 = 5, etc. In such a way, since the operation 2/2, represents 2 ÷ 2, it is clear that two is once in 2, therefore, the result is:

2 ÷ 2 = 1.

Best regards!

Why do stretching exercises increase flexibility more than cardio exercises?

Answers

cardio exercise improve the strength of the limbs. C.) cardio exercises consist of fluid movements. D.) carido exercises depend on increased oxygen ...

What two methods are the best choices to factor this expression 18x2-8

Answers

Answer:

Please check the explanation

Explanation:

The best two methods will be:

Factor by groupingFactor out the GCF

Factor by grouping

Factor by grouping deals with establishing a smaller groups from each term.

[tex]18x^2=\:\left(2\cdot 3\cdot 3\cdot x^2\right)[/tex]

[tex]8\:=\:\:2\cdot 2\cdot 2[/tex]

Therefore, the expression becomes

[tex]18x^2=\:\left(2\cdot 3\cdot 3\cdot x^2\right)-\left(2\cdot \:2\cdot \:2\right)[/tex]

Now factor out the greatest common factor (GCF) which is 2

         [tex]=\:2\left(3\cdot \:\:3x^2-\left(2\right)\left(2\right)\right)[/tex]

           [tex]=2\left(9x^2-2\cdot \:2\right)[/tex]

            [tex]=2\left(9x^2-4\right)[/tex]

Factor out the GCF

Given the expression

[tex]18x^2-8\:\:\:[/tex]

factor out common term 2

[tex]=2\left(9x^2-4\right)[/tex]

[tex]=2\left(3x+2\right)\left(3x-2\right)[/tex]          ∵ [tex]Factors\:\:\left(9x^2-4\right)=\left(3x+2\right)\left(3x-2\right)[/tex]

A crate of books rests on a level floor. To move it along the floor at a constant velocity, why do you exert less force if you pull it at an angle Ï above the horizontal than if you push it at the same angle below the horizontal?

Answers

Answer:should be a matter of vector analysis.

Pulling above the horizontal has less surface area for the opposing friction

Explanation:

Two stars in a faraway part of the Milky Way are orbiting each other as a binary star system. By
careful measurement we find out that they are separated by 1.7 AU. We also determine that
their orbital period is 594 Earth-days. The total mass of the two-object system is

Answers

Answer: [tex]M_{total}=[/tex] 1.85

Explanation: Estimate the total mass of a binary system is done by a reformulation of Kepler's Third Law, which states that the square of the period of a planet's orbit is proportional to the cube of its semimajor axis, i.e.:

[tex]a^{3}=(M_{1}+M_{2})P^{2}[/tex]

where

a is semimajor axis in astronomical units (AU);

P is period measured in years;

[tex]M_{1}+M_{2}[/tex] is total mass of the two-stars system;

For the two stars faraway in the Milky Way:

1 year is equivalent of 365 days, so period in years:

[tex]P=\frac{594}{365}[/tex]

P = 1.63 years

Calculating total mass:

[tex]a^{3}=(M_{total})P^{2}[/tex]

[tex]M_{total}=\frac{a^{3}}{P^{2}}[/tex]

[tex]M_{total}=\frac{1.7^{3}}{1.63^{2}}[/tex]

[tex]M_{total}=[/tex] 1.85

The total mass of the two-object system is 1.85 mass units.

A car is moving at an average speed of 20 meters per second. This is equivalent to

Answers

Answer:

44.73 MP/H or 71.98 KM/H

Explanation:

Two parallel 3.0-meter long wires conduct current. The current in the top wire is 12.5 A and flows to the right. The top wire feels a repulsive force of 2.4 x 10^-4 N created by the interaction of the 12.5 A current and the magnetic field created by the bottom current (I). Find the magnitude and direction of the bottom current.

Answers

Complete question:

Two parallel 3.0-meter long wires conduct current. The current in the top wire is 12.5 A and flows to the right. The top wire feels a repulsive force of 2.4 x 10^-4 N created by the interaction of the 12.5 A current and the magnetic field created by the bottom current (I). Find the magnitude and direction of the bottom current, if the distance between the two wires is 40cm.

Answer:

The bottom current is 12.8 A to the right.

Explanation:

Given;

length of the wires, L = 3.0 m

current in the top wire, I₁ = 12.5 A

repulsive force between the two wires, F = 2.4 x 10⁻⁴ N

distance between the two wires, r = 40 cm = 0.4 m

The repulsive force between the two wires is given by;

[tex]F = \frac{\mu_oI_1I_2L}{2\pi r}\\\\I_{2} = \frac{2F\pi r}{\mu_oI_1L}[/tex]

Where;

I₂ is the bottom current

The direction of the bottom current must be in the same direction as the top current since the force between the two wires is repulsive.

[tex]I_{2} = \frac{2F\pi r}{\mu_oI_1L}\\\\I_{2} = \frac{2(2.4*10^{-4})(\pi)(0.4)}{(4\pi*10^{-7})(12.5)(3)}\\\\I_{2} = 12.8 \ A[/tex]

Therefore, the bottom current is 12.8 A to the right.

show all work and round to nearest 100th thank you and you will get braineist ​

Answers

Answer:  16.78 miles

Explanation:

distance = rate * time

we're given the rate ( 5 m/s) and we're given the time it takes to get home (1.5 hrs). But notice how the units of hours don't match the seconds of the rate so we need to convert the hours into seconds.

1 hr = 3600 seconds so 1.5 hours = 5400 seconds

now we can plug it in and solve for the distance

distance = (5 m/s) * 5400 seconds

distance = 27000 m

now we have to convert meters to miles, so we divide our answer by 1609 and get 16.78

If a penny is dropped from rest from a tower takes 2 seconds to hit the ground, how far did it travel?

a 29.4 m
b 19.6 m
с 6.8 m
d 9.8 m​

Answers

Answer:

B

Explanation:

t = 2s

u = 0m/s (released from rest)

a = +g = 9.8m/s²

s = H = ?

using,

s = ut + 1/2at²

H = 0(2) + 1/2(9.8)(2²)

H = 0 + 9.8(2)

s = H = 19.6m

Which image illustrates the interaction of a light wave with a mirror?
t J
A
с
.
A. A
B. B
C. C
D. D
0

Answers

Answer:

I'm pretty sure its A

Explanation:

because its a reflection- Hope you get a good grade!

A potential difference of 1.20 V will be applied to a 33.0 m length of 18-gauge copper wire (diameter = 0.0400 in.). Calculate (a) the current, (b) the magnitude of the current density, (c) the magnitude of the electric field within the wire, and (d) the rate at which thermal energy will appear in the wire.

Answers

Answer:A) Current = 1.739A, B)current density, J = 2.147x10^6 A/m2

magnitude of electric field , E =  0.036 N/C

)rate of thermal energy, P  =2.086W

Explanation:

Resistance  = R =   ρL/A

But the cross-section area of the wire. is given as

Diameter / 2 = 0.04/2 =0.02in to m = 0.02 / 39.37= 0.000508

A = πr^2 = π x  0.000508^2 = 8.10 x 10^-7

since resistivity of copper,ρ= 17x10-9 ohm.m

so resistance is   R =   ρL/A

17x10-9  x 33 / 8.1x10-7

= 0.69 ohm.

A) Current =    I = Voltage /Resistance =1.20/0.69 =1.739A

B)current density, J = Current /Area

= 1.739/8.1x10-7

= 2.147x10^6 A/m2

c)magnitude of electric field , E =  Current density x resistivity =J ρ

E = 2.147 x 10^6  x 17  x 10^-9

E = 0.036 N/C

D)rate of thermal energy, P  = I² R =1.739² X 0.69

=2.086W

Which is the goal of technology?


to expand comprehension

to make life easier

to apply knowledge

to improve communication
pls help

Answers

Answer:

i think it should be to make life easier

i think it would be make life easier

A football player runs down the field at a speed of 8 m/s how long will it take him to run 20 m?

Answers

The answer is simple. Since the football player runs at 8m/s and you are trying to find out how long it will take him to run 20 m, you simply divide 20/8.

The answer to this would be 2.5 seconds for the football player to run 20 meters.
I hope I did this problem correct and I hope that this helped you :)))

Are the refractive index and the speed of light in a vacuum direct propotional or inversley​

Answers

The refractive index of the medium is inversely proportional to the velocity of light in it. As the refractive index of a medium increases, the speed of light going through that medium decreases.

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