A commuter train passes a passenger platform at a constant speed of 39.6 m/s. The train horn is sounded at its characteristic frequency of 346 Hz. (a) What overall change in frequency is detected by a person on the platform as the train moves from approaching to receding

Answers

Answer 1

Answer:

Explanation:

We shall apply Doppler's effect to solve the problem .

Formula for apparent frequency for a source of sound approaching an observer is as follows .

f₁ = f₀ V / (V - v )

where f₁ and f₀ are apparent and real frequency of source , V and v is velocity of sound and velocity of approaching source respectively .

Putting the given values and knowing that speed of sound is 340 m /s

f₁ =346x 340 / (340 - 39.6 )

f₁ = 391.6 Hz

In case of receding train , the formula is

f₂ = f₀ V / (V + v )

Putting the values

f₂ = 346x 340 / (340 + 39.6 )

= 309.9 Hz

Change in frequency =  391.6 - 309.9

= 81.7 Hz .


Related Questions

A car company is doing crash tests and has installed forcesensors in the chairs and seatbelts to measure the forces thatare exerted on crash test dummies during a crash. In oneparticular test the sensors measure a horizontal net force onthe dummy of 39,400 N when the car comes to a complete stopfrom an initial speed of 35 m/s in 1.4 m. Treating the dummyas a point particle and assuming it comes to rest in the samedistance, what is the mass of the test dummy used during thistest

Answers

Answer:

[tex]m=90.1kg[/tex]

Explanation:

From the question we are told that

Force F=39400

Initial speed [tex]V_1=35m/s[/tex]

Distance[tex]d=1.4m[/tex]

Generally the equation for acceleration is mathematically given by

[tex]a=\frac{V^2-U^2}{2d}[/tex]

[tex]a=\frac{0^2-35^2}{21.4}[/tex]

[tex]a=\frac{0^2-35^2}{21.4}[/tex]

[tex]a=-437.5m/sec^2[/tex]

Generally the equation for mass is mathematically given by

[tex]F=ma\\m=F/a[/tex]

[tex]m=\frac{-39400}{-437.5}[/tex]

[tex]m=90.1kg[/tex]

1) The cause of magnetism is
A. atoms forming “domains” that are arranged randomly
B. atoms forming "domains” that are arranged uniformly
C. atoms forming "dolomites” that are arranged randomly
D. atoms forming “dolomites” that are arranged uniformly

Answers

Answer:

I think it's A, I'm not sure though

Which of the following examples, would best represent the input energy and then
'wasted energy forms when watching TV.
A. Chemical, and then heat and electrical.
B. Chemical, and then heat, kinetic, sound
C. Electrical, and light, sound, heat
D. Electrical, and then sound and heat

Answers

Answer:

I think the answer is c electrical, and light , sound hewt

during what part of their drive are the not moving?

Answers

C answer is c math ez
The correct answer is c

Can anyone help me with the Wet Lab Guide - Coulomb's Law report? I'm really having trouble with it. I have attached the worksheet

Answers

Answer:

Coulomb's law of Electrostatic Force states that a charged particle attracts or repels other charged particles with a force which is directly proportional to the product of their charges and inversely proportional to the square of the distance between their centers.

Explanation:

A man standing on the Earth can exert the same force with his legs as when he is standing on the moon. We know that the mass of the man is the same on the Earth and the moon. We also know that F=ma is true on both the Earth and the moon. Will the man be able to jump higher on the moon than the Earth? Why or why not?
PLEASE HELPPPP

Answers

Answer:

yes

Explanation:

earth has gravity force that is high than the moon gravity force which is 1/6 of earth gravity

Earth has gravity force that is high than the moon gravity force which is 1/6 of earth gravity.

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.

The force on the moon is less than earth as gravity is 1/6 on the moon

When man jump than he will jump high on the moon than the earth.

Earth has gravity force that is high than the moon gravity force which is 1/6 of earth gravity.

To learn more about force refer to the link:

brainly.com/question/13191643

#SPJ2

Calculate the x-component of the electric field at point P due to charge Q1. Write your answer in units of N/C.

Answers

This question is incomplete, the complete question is;

A positive charge of magnitude Q1 = 6.5 nC is located at the origin.

A negative charge Q2 = -3.5 nC is located on the positive x-axis at x = 16.5 cm from the origin. The point P is located y = 10.5 cm above charge Q2.

Calculate the x-component of the electric field at point P due to charge Q1. Write your answer in units of N/C.

Answer:

the x-component of the electric field at point P due to charge Q1 is 1291.33 N/C    

Explanation:

Given the data in the question;

Q1 = 6.5 nC, Q2 = -3.5 nC

from the image below, to get our angle ∅

tan∅ = opp/adj

tan∅ = 10.5 / 16.5

tan∅ = 0.636363

∅ = tan⁻¹( 0.636363 )

∅ = 32.47°

also, r1 = √( 16.5² + 10.5²)

r1 = √( 272.25 + 110.25 )

r1 = √382.5

r1 = 19.55 cm = 0.1955 m

Now, the x-component of the electric field at point P due to charge Q1 will be;

Ex = E2cos32.47°

= (kQ1/r1²)cos32.47°

we know that;  k is Coulomb's law constant ( 9 × 10⁹ N.m²/ C²

Q1 = 6.5 nC = 6.5 × 10⁻⁹ C

so we substitute

= ((9 × 10⁹ × 6.5 × 10⁻⁹) / (0.1955)²) cos32.47°

= (58.5 / 0.03822025) × 0.843672

= 1291.33 N/C

Therefore, the x-component of the electric field at point P due to charge Q1 is 1291.33 N/C

Besides gravity, what factor keeps the moon and Earth in orbit?

force
inertia
mass
distance

Answers

Answer:

interna

Explanation:

please mark as brainllest

Answer is inertia
Good Luck ;)

how does different color show exist

Answers

Answer:Light is made up of wavelengths of light, and each wavelength is a particular colour. The colour we see is a result of which wavelengths are reflected back to our eyes. The visible spectrum showing the wavelengths of each of the component colours. The spectrum ranges from dark red at 700 nm to violet at 400 nm.  

Explanation:

hope it helps

Answer:When light hits an object, the object reflects some of that light and absorbs the rest of it. Some objects reflect more of a certain wavelength of light than others. That's why you see a certain colour. For example, a lemon reflects mainly yellow light.

Explanation:

Suppose that 6 J of work is needed to stretch a spring from its natural length of 28 cm to a length of 43 cm. (a) How much work is needed to stretch the spring from 33 cm to 38 cm

Answers

Answer:

Workdone = 0.67 Joules

Explanation:

Given the following data;

Workdone = 6J

Extension = 43 - 28 = 15cm to meters = 15/100 = 0.15m

The workdone to stretch a string is given by the formula;

Workdone = ½ke²

Where;

k is the constant of elasticity.

e is the extension of the string.

We would solve for string constant, k;

6 = ½*k*0.15²

6 = ½*k*0.0225

Cross-multiplying, we have;

12 = 0.0225k

k = 12/0.0225

k = 533.33N/m

a. To find the workdone when e = 33, 38.

Extension = 38 - 33 = 5 to meters = 5/100 = 0.05m

Workdone = ½*533.33*0.05²

Workdone = 266.67 * 0.0025

Workdone = 0.67 Joules

Therefore, the amount of work (in J) needed to stretch the spring from 33 cm to 38 cm is 0.67.

Orchestra instruments are commonly tuned to match an A-note played by the principal oboe. The Baltimore Symphony Orchestra tunes to an A-note at 440 Hz while the Boston Symphony Orchestra tunes to 442 Hz. If the speed of sound is constant at 343 m/s, find the magnitude of difference between the wavelengths of these two different A-notes. (Enter your answer in m.)

Answers

Answer:

Δλ = 3*10⁻³ m.

Explanation:

At any wave, there exists a fixed relationship between the speed of  the wave, the wavelength, and the frequency, as follows:

       [tex]v = \lambda* f (1)[/tex]

       where v is the speed, λ is the wavelength and f is the frequency.

Rearranging terms, we can get λ from the other two parameters, as follows:

       [tex]\lambda = \frac{v}{f} (2)[/tex]

Since v is constant for sound at 343 m/s, we can find the different wavelengths at different frequencies, as follows:

        [tex]\lambda_{1} =\frac{v}{f_{1}} = \frac{343m/s}{440(1/s)} = 0.779 m (3)[/tex]

        [tex]\lambda_{2} =\frac{v}{f_{2}} = \frac{343m/s}{442(1/s)} = 0.776 m (4)[/tex]

The difference between both wavelengths, is just the difference between (3) and (4):

       [tex]\Delta \lambda = \lambda_{1} - \lambda_{2} = 0.779 m - 0.776m = 3e-3 m (5)[/tex]

       ⇒ Δλ = 3*10⁻³ m.

The floor on a dance hall can take a pressure of 3.5MPa before getting damaged. A lady of mass 60kg wears high heeled shoes. What is the smallest area of the sole of a heel she could wear such that it won't permanently damage the floor

Answers

Answer:

smallest area of the heel is 0.000168  m^2

Explanation:

Recall that pressure is defined as: Force / area. Therefore to reach a pressure of 3,500,000 Pa using a force: m * g = 60 kg * 9,8 m/s^2 = 588 N, one needs:

Area = 588 / 3500000 m^2 = 0.000168  m^2

can someone help me :(​

Answers

Answer:

1. This is a speed graph.

2. The slope represents how much the item/ thing is moving at how much distance it moved and the minutes it takes it too move how much distance, but the slope is representing the decrease and increase of it.

3. Increasing, kind of rapidly going up since the slope is rising not falling.

You are standing on a street corner with your friend. You then travel 14.0 m due west across the street and into your apartment building. You travel in the elevator 22.0 m upward to your floor, walk 12.0 m north to the door of your apartment, and then walk 6.0 m due east to your balcony that overlooks the street. Your friend is standing where you left her.
Now how far are you from your friend?
Express your answer with the appropriate units.

Answers

Answer:

Explanation:

We shall express each displacement vectorially , i for each unit displacement towards east , j for northward displacement and k for vertical displacement .

14 m due west = - 14 i

22.0 m upward in the elevator = 22 k

12 m north = 12 j

6.00 m east = 6 i

Total displacement = - 14 i + 22 k + 12 j + 6 i

D = - 8 i + 12 j + 22 k

magnitude = √ ( 8² + 12² + 22² )

= √ ( 64 + 144 + 484 )

= √ 692

= 26.3 m

Net displacement from starting point = 26.3 m .

If a large number of waves pass by a certain point in a given time, the waves have a low frequency. none of the above. a high frequency. it doesn't affect frequency.

Answers

Answer:

Another term used to describe a wave is frequency. Since waves are moving, we define frequency as the number of waves that pass a given point in a specified unit of time. The unit commonly used is Hertz which is the number of wave cycles pass a point in one second. So one cycle per second equals one Hertz

Consider a 2 m wide and 5 m long slab resting on flat, fixed, earthen bed. The slab is 20 cm thick with uniform properties. You may assume the slab is much longer and wider than it is thick. Write the reduced form of the governing equation for the slab. Clearly identify your coordinate system on a sketch and state your assumptions identifying which terms you are eliminating and why.

Answers

Answer:

Explanation:

The coordinate sketch for the system is shown in the attached file below. Also, in the cartesian coordinate system, since the height is less than the length and width, we did neglect the height. Thus, we eliminate the height and converted it to a two-dimension.

What is the kinetic energy of a 30 kg dog that is running at a speed of 8.6 m/s (about 19 mi/h)?

Answers

Answer:

Uhm thags hsed

Explanation:

Dkrr

I need help with this question

Answers

Option 3) a Soccer Ball

will travel the farthest distance.

Answer:

a bowling ball

pls follow me and Mark as brainliest and follow me to get free thanks to all your answers

Galileo is considered the father of modern science. Do you agree with this description? Give reasons for your answer.

Answers

Answer:

Galileo Galilei pioneered the experimental scientific method and was the first to use a refracting telescope to make important astronomical discoveries

Explanation:

Yes I agree with this. He made significant scientific discoveries that changed the way of life.

Which equation will tell you the acceleration of the object?

Answers

Answer:

In summation, acceleration can be defined as the rate of change of velocity with respect to time and the formula expressing the average velocity of an object can be written as: a =Δ v/ Δt The other 4 equations: d = vit+ (1/2) at2

Explanation:

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