An observer is standing next to the tracks, watching a train approach. The train travels at 30 m/s and blows its whistle at 8,000 Hz as it approaches and then passes by the observer without slowing down. Assuming the speed of sound is 340 m/s, how much of a frequency change did the observer hear?

Answers

Answer 1

7351.35Hz

f0= v-Vo/v-Vs × FSA

= 340-0 /340+30 ×8000

= 340/370× 8000

= 7351.35hz


Related Questions

15millas a km alguien pliss para ahorita porfa lo sigo

Answers

Answer:

X = 24.135 kilometres

Explanation:

Given the following data;

Distance = 15 miles

To convert the value in miles to kilometers;

Conversion:

1 mile = 1.609 kilometres

15 miles = X kilometres

Cross-multiplying, we have;

X = 1.609 * 15

X = 24.135 kilometres

ASAP!! Please help me out here ​

Answers

Answer:

Option: D

Explanation:

As,

In Option,

A:

There are two same positive ions so they will move away from each other.

B:

There is one negative and positive ion so they will move towards each other.

C:

Again there is one negative and positive ion so they will move towards each other.

D:

Here, there is neutral ions so they will not move and its the correct option.

Một bóng đèn có hiệu điện thế định mức là 110V. Đặt vào hai đầu bóng đèn các hiệu điện thế sau đây, hỏi trường hợp nào dây tóc của đèn sẽ đứt?

Answers

Answer:

fhaiisjrbekxkrkebxnsiiwj4bnds

You observe that you see more mockingbirds in small trees and more hawks in large trees. Which of the following is an appropriate scientific question based on this observation?
How does the size of a tree affect the bird species that prefer to live in it?
How do birds fly?
What type of food do birds eat?
What time of year to birds mate?

Answers

Hi! I think the answer is How does the size of a tree defect the bird species that prefer to live in it or option A. I would go with this option because it is the most logical answer. Option B doesn’t really have anything to do with why the two different types are picking different size of trees to live in. Option C. seems like the second most logical answer. Option D. Wouldn’t make the different types of birds pick different trees It shouldn’t matter when they mate if they are staying in the same types of trees. I hope this helped, Goodluck :)

Answer:

A) How the size of a tree affect the bird species that prefer to live in it

Explanation:

I took the quiz

Fifty (50) grams of vinegar and (2) grams of baking soda are mixed together. A bubbling reaction takes place. The mixture is weighed again and now weighs 49 grams. How do you explain the missing weight? ​

Answers

Answer:

the gas that escaped from the mixture contained the missing weight

why Fossil fuel has been used more in the existing world ?​

Answers

Fossil fuels are found most of the part of the world .It can be found easily by the people.It is free of cost or low cost.Thats why people can find it easily and in low cost.Also it is easy to useSo fossil fuel has been used more in existing world

which species are near extinctions and where do they live now?

Answers

Answer:

Amur Leopard, Southeastern Russia, and northern china

Explanation:

Answer:

Amur Leopard    China/Russia

Hawks bill Turtle   live in Oceans

if a girl is running along a straight road with uniform velocity 1.5 metre per second find the acceleration​

Answers

Answer:

Acceleration is 0.

Explanation:

Since the girl is running with a uniform velocity, meaning she is moving at a constant rate, she is not accelerating. Acceleration only occurs when the speed of an object increases, decreases, or if there is a change in direction.

can anyone help me to explain theory of relativity??? ​

Answers

Answer:

The theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity, proposed and published in 1905 and 1915, respectively. Special relativity applies to all physical phenomena in the absence of gravity. General relativity explains the law of gravitation and its relation to other forces of nature.It applies to the cosmological and astrophysical realm, including astronomy.

The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction. In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. With relativity, cosmology and astrophysics predicted extraordinary astronomical phenomena such as neutron stars, black holes, and gravitational waves

Most solar hot water systems are fitted with gas or electric "boosters" that can also heat the water.

Describe why you think these are necessary.

DUE IN 2 HOURS PLEASE HELP!!

Answers

To provide hot water on cloudy days or when demand exceeds supply, most solar water heaters come with a gas or electric booster. A gas booster usually produces fewer greenhouse gas emissions unless renewable electricity is used or the booster is a heat pump.

A man pulls his luggage on a 30 degree incline with a constant force of 25 N. How
much work does he do after walking 20.0 m?
a) 430 J
b) 330J
c) 1500J
d) 250 J

Answers

Force=F=25NDisplacement=s=20mAngle=30°

We know

[tex]\boxed{\sf W=Fscos\theta}[/tex]

[tex]\\ \sf\longmapsto W=25(20)cos30°[/tex]

[tex]\\ \sf\longmapsto W=500\times \dfrac{\sqrt{3}}{2}[/tex]

[tex]\\ \sf\longmapsto W=250\sqrt{3}[/tex]

[tex]\\ \sf\longmapsto W=250(1.73)[/tex]

[tex]\\ \sf\longmapsto W\approx 430J[/tex]

Option a) 430 J work done he do after walking 20.0 m.

What is work?

Work, in physics, is a measure of energy transfer that happens when an object exists moved over a distance by an external force at least part of which exists involved in the direction of the displacement.

Displacement exists as the distance moved in a straight line, in a provided direction, from the starting point. Displacement exists as a vector quantity as it includes size and direction.

An angle stands the figure formed by two rays, named the sides of the angle, sharing a standard endpoint, named the vertex of the angle.

Force=F=25NDisplacement=s=20mAngle=30°

⇒[tex]W=Fcos\theta[/tex]

⇒[tex]W=25(20)cos 30^{0}[/tex]

Then,

⇒[tex]W=50*\sqrt{3} /2[/tex]

⇒[tex]W=250\sqrt{3}[/tex]

Hence,

⇒[tex]W=250(1.73)[/tex]

[tex]W[/tex] approximately 430J.

Hence, Option a) 430 J work done he do after walking 20.0 m.

To learn more about Displacement refer to:

https://brainly.com/question/321442

#SPJ2

define amplitude & period of the particle performing linear S.H.M​

Answers

Answer:

This type of a behavior is known as oscillation, a periodic movement between two points. ... Amplitude: The distance from the center of motion to either extreme. Period: The amount of time it takes for one complete cycle of motion.

Explanation:

Amplitude (a):- The maximum displacement of particle from its mean position on either side is called amplitude.  

Periodic time:- The time taken by a wave to complete one oscillation is called periodic time.

6. A car moving in a straight line at constant speed:
A. is accelerating.
B. is decelerating.
C. must be on a downhill slope.
D. has no overall force acting on it.

Answers

Answer:

D. has no overall force acting on it.

Explanation:

Why?

Because in a straight line at the constant speed means the car moving in the same velocity, which is not acceleration neither deceleration, and it cannot be on a downhill slope. So the correct answer is

→ D. has no overall force acting on it.

A block of amber is placed in water and a laser beam travels from the water through the amber. The angle of incidence is 35 degrees while the angle of refraction is 24 degrees. What is the index of refraction of amber?

(index of refraction of water is 1.33)

Answers

Answer: 1.88

Explanation

Applying Snell’s Law, sin(1)/sin(2) = n(2)/n(1), where n is the index of refraction and sin 1 and 2 being of incidence and refracted respectively.

1) sin35/sin24 = n(2)/1.33
2) 1.41 = n(2)/1.33
3) n(2) = 1.41 x 1.33
4) n(2) = 1.88

Hope this helps :)

Why are road accidents at high speeds very much worse than road accidents at low speeds?

Answers

Answer:

The momentum makes it worse.

Explanation:

The momentum of vehicles running at faster speeds is very high and causes a lot of damage to the vehicles.

Vehicles with high speeds have high momenta (plural of momentum). When they come to rest in very small time they experience high forces
we know that rate of change of momentum is force, lower the time higher is force. So, slow moving vehicles experience less force. It is important to note that if any one vehicle involving has high speed it can do more damage both the vehicles involving.

Value of g increases with the
(a) increase in mass of the body
(b) increase in altitude
(c) decrease in altitude
(d) none of the above

Answers

Answer:

increase in mass of body

How does the comets energy change as it moves from point a to point d

Answers

Answer:

At point A, the comet has the least kinetic energy because the comet is resting. 3. From point B to point D its orbit's potential energy is decreasing and its kinetic energy is increasing meaning it's moving more and more

direct or indirect
"Susan is a lovely ten-year-old girl from Hawaii."

Answers

Answer:

Direct

Explanation:

what is efficiency of a machine?

Answers

Mechanical efficiency is a measure of how well the machine converts the input work or energy into some useful output. It is calculated by dividing the output work by the input work. The ideal machine has mechanical efficiency equal to unity, while the real machine has mechanical efficiency less than unity

Answer:

Efficiency of a machine is defined as the ratio of output work to input work in a machine . It is expressed in percentage and denoted by

η ( eta).

Ella is blowing up balloons in preparation for her sister's birthday. Ella finds some balloons hanging outside the house explode after a few hours. Explain why.​

Answers

Answer:

they were in the sun for long

how to find the mechanical advantage

Answers

To determine its mechanical advantage you'll divide the length of the sloped side by the width of the wedge. For example, if the slope is 3 centimeters and the width is 1.5 centimeters, then the mechanical advantage is 2, or 3 centimeters divided by 1.5 centimeters.

Answer:

[tex]{ \bf{mechanical \: adv = \frac{load}{effort} }}[/tex]

3. Take sugar, oil, corn syrup, a glass and water. Pour the water in the glass and then add each of the above the substances one after the other. Observe and note your observations. And give reason for your observation.

Answers

Here are the observations

Sugar:-

Sugar is soluble in water so It will dissolve in water .

Corn syrup:-

Corn syrup is also basically a sugar.It will dissolve in water too .If we shake the mixture in glass then corn syrup will be dissolved.

Oil:-

Oil is not soluble in waterHence it won't dissolve in water.It will float over water and make two layers

Group elements number 11 to 20 as either metallic, non metallic or metalloid.​

Answers

Answer:

The elements are grouped into the different substances by color. As you can see, Lithium, Beryllium, Sodium, Magnesium, Aluminum, Potassium, and Calcium are metals out of the first 20 elements.

Hydrogen, Helium, Carbon, Nitrogen, Oxygen, Fluorine, Neon, Phosphorus, Sulfur, Chlorine, and Argon, are non-metals within the first 20 elements.

Boron and Silicon count as Metalloids in the Periodic Table (properties of both metals and non-metals)

reference- socatric q and a

Explanation:

Answer:

(11-13) - Metals

(14) - Metalloid

(15-18) - Non- metals

(19-20) - Metals

Explanation:

The elements from 11 to 13 are metals. They are Sodium(Na), Magnesium(Mg) and Aluminum(Al) respectively.

The element 14 is a metalloid. It’s Silicon(Si).

The elements from 15 to 18 are non metals. The 18th element is a noble gas known as Argon(Ar).

The elements from 15 to 17 are Phosphorus(P), Sulphur(S) and Chlorine(Cl).

The elements from 19 to 20 are metals. They are Potassium(K) and Calcium(Ca).

how many significant figures 216 m

Answers

Answer:

Three

Explanation:

I hope this helps:)

to all the physicians please help this is for my assignment

Answers

Answer:

Q. 1. Newton's Law of gravitation states that all bodies in the universe exerts a force of attraction on all other bodies in the universe with a proportional force to both the product of the masses of the bodies and inversely proportional to the square of the distance between their centers

Mathematically, we have;

[tex]F = G \times \dfrac{m_1 \times m_2}{R^2}[/tex]

Where;

m₁, and m₂ are the masses of the bodies

R = The distance between their centers

G = The gravitational constant = 6.6743 × 10⁻¹¹ N·m²/kg²

The gravitational constant, G, is the Newton's law of gravitation's constant of proportionality between the force of attraction that exist two bodies and the product of their masses divided by the square of the distance between their centers

Q. 2. Newton's law of gravitation in vector form is presented as follows;

[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12}[/tex]

The above equation gives the gravitational force of attraction of body 1 on body 2, with the negative sign and unit vector indicating that the force of of gravity is towards body 1

The force of gravity of body 2 on 1 is presented as follows;

[tex]\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{12}^2} \cdot \hat R_{21}[/tex]

The gravitational force of attraction of body 2 on body 1 is therefore, equal in magnitude and opposite in direction of the gravitational force of body 1 on body 2 (towards body 2)

[tex]-\underset{F_{12}}{\rightarrow} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{12} = G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot -(\hat R_{21}) = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21}[/tex]

[tex]-\underset{F_{12}}{\rightarrow} = -G \times \dfrac{m_1 \times m_2}{R_{21}^2} \cdot \hat R_{21} = \underset{F_{21}}{\rightarrow}[/tex]

[tex]-\underset{F_{12}}{\rightarrow} = \underset{F_{21}}{\rightarrow}[/tex]

Explanation:

A car is moving with the velocity of 90km/h. If the car come to rest after 10 seconds. Calculate the final velocity and distance covered by the car within that time.

plz wirte the full formula ​

Answers

Answer:

you can learn from here

https://www.toppr.com/ask/en-bd/question/a-car-is-moving-with-a-velocity-of-10-ms-the-driver-sees-a-wall/

PRESS THE PHOTO NEED HELP!!! 30 POINTS

Answers

1:-

[tex]\\ \sf\longmapsto cos\Theta=\dfrac{B}{H}[/tex]

[tex]\\ \sf\longmapsto cos\Theta=\dfrac{4}{5}[/tex]

2:-

[tex]\\ \sf\longmapsto tan\Theta=\dfrac{P}{B}[/tex]

[tex]\\ \sf\longmapsto Tan\Theta=\dfrac{3}{4}[/tex]

Key Notes:-

P denotes to Perpendicular.B denotes to Base.H denotes to Hypotenuse.

Answer:

Cos A = 4/5

Tan A = 3/4

Explanation:

Cos A = Adjacent/Hypotenuse = 4/5

Tan A = Opposite/Adjacent = 3/4

Global warming is threatening polar bear habitats and the bears' way of life. If trends continue, predict what will become of the polar bear in the next 10,000 years. Will it adapt or become extinct? Defend your answer.

Answers

it will become a stink. It will become extinct because if people keep doing what you’re doing it will get no better.

Bear will become extinct due to global warming.

What is greenhouse gas?

The gases which get easily trapped inside the glasses and increase the temperature of the atmosphere causing the global warming level to increase overall.

Global warming is threatening polar bear habitats and the bears way of life. If global warming continues, predict what will become of the polar bear in the next 10,000 years

Thus, bear will extinct.

Learn more about greenhouse gas.

https://brainly.com/question/4509458

#SPJ2.

if A vector = i^-j^+k^ then unit vector in the direction of A vector
a)√3,j^
b)(i^-j^+k^)
c)(i^-j^-k^)/√2
d)(i^-j^+k^)/√3
plzz answer my question with explanation​

Answers

If A = i - j + k, then the magnitude of A is

||A|| = √(1² + (-1)² + 1²) = √3

Then the unit vector in the direction of A is 1/||A|| multiplied by A :

u = A/||A|| = (i - j + k)/√3

(choice D)

What is concave mirror?​

Answers

Answer:

A concave mirror, or converging mirror, has a reflecting surface that is recessed inward (away from the incident light). Concave mirrors reflect light inward to one focal point. They are used to focus light.

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