1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
vodka [1.7K]
3 years ago
7

A train is traveling away from you at 120 km/h. It blows its whistle, and you hear a tone of 0.400 kHz. Take the speed of sound

to be 340 m/s. What frequency does the whistle actually produce
Physics
1 answer:
Margaret [11]3 years ago
8 0

Answer:

The actual frequency produced by the train whistle is 444 Hz.

Explanation:

Given;

speed of the train, Vs = 120 km/h = 33.33 m/s

observed frequency, Fo = 0.4 kHz = 400 Hz

speed of sound in air, V = 340 m/s

<u>Note:</u> as the train moves away, the observed frequency will be smaller than the source frequency. Thus, the source frequency which is frequency of the train whistle will be greater than 400 Hz.

The source frequency is given by Doppler effect formula;

F_s = F_o [\frac{V}{V-V_s} ]\\\\F_s = 400[\frac{340}{340-33.33} ]\\\\F_s = 400(1.109)\\\\F_s = 443.6 \ Hz

Fs = 444 Hz

Therefore, the actual frequency produced by the train whistle is 444 Hz.

You might be interested in
Estimate the mass of water that must evaporate from the skin to cool the body by 0.45 ∘C. Assume a body mass of 95 kg and assume
hram777 [196]

Answer:

0.0757 kg

Explanation:

m = mass of the body = 95 kg = 95000 g

ΔT = change in the temperature of the body = 0.45 °C

c = specific heat capacity of the body = 4.0 J/(g °C)

M = mass of water evaporated

L = latent heat of vaporization of water = 2260 J/g

Using conservation of heat

Heat gained by water = heat lost by body

ML = m c ΔT

M (2260) = (95000) (4.0) (0.45)

M = 75.7 g

M = 0.0757 kg

4 0
3 years ago
Solve 305809 square root by division method​
Rus_ich [418]
You use long division.

Find the largest number whose square is less than or equal to the number in the leftmost group (55 < 30 < 66). Take this number as the divisor and the quotient with the number in the leftmost group as the dividend (30). Divide and get the remainder (5 in this case).

Bring down the next pair 58. Add the divisor with the quotient and enter it with a blank on its right. Guess a largest possible digit to fill the blank which will also become the new digit in the quotient, such that when the new divisor is multiplied to the new quotient the product is less than or equal to the dividend. In this case 105 × 5 = 525, so we choose the new digit as 5. Get the remainder.

Bring down the next pair 09. Add the divisor with the quotient and enter it with a blank on its right. Guess a largest possible digit to fill the blank which will also become the new digit in the quotient, such that when the new divisor is multiplied to the new quotient the product is less than or equal to the dividend. In this case 1103 × 3 = 3309, so we choose the new digit as 3. Get the remainder.

Put the decimal point.

End of division (Remainder is 0 and next digit after decimal is 0).

√305809 = 553
8 0
4 years ago
Traditional Indonesian music uses an ensemble called a gamelan that is based on tuned percussion instruments somewhat like gongs
Vlada [557]

Answer:

n = 10 beats

Explanation:

Given:

- Frequency of note f1 = 151 Hz

- Frequency of note f2 = 155 Hz

- The total time they ring t = 2.5 s

Find:

How many beats are heard

Solution:

- The frequency of beat (fb) is the difference between the two frequencies of notes as follows:

                                fb = f2 - f1

                                fb = 155 - 151

                                fb = 4 Hz

- The number of beats per second is also called beat frequency:

                                n = fb*t

                                n = 4*2.5

                                n = 10 beats

           

3 0
4 years ago
Global average temperature increases when energy absorbed by the surface ___?
MAXImum [283]

Answer:

se elevator a maas eneergia mas alta

8 0
3 years ago
A petrol engine that transforms 1000J of chemical potential energy into 300J of kinetic energy, and 700J into wasted heat and so
sergey [27]

Answer:

Efficiency = 30% = 0.3

Explanation:

The general formula for efficiency of a device is given as:

Efficiency = (Desired Output/ Input) * 100%

Here, in our case, we have a petrol engine as a device. So, we analyze it for the efficiency calculations. Here, we have:

Chemical Potential Energy = 1000 J

Kinetic Energy = 300 J

Heat and Sound Energy = 700 J

Now, we know that the desired output of a car or the purpose of a car is to provide Kinetic energy, while all other forms of energy such as heat and sound energies are produced as waste. And the chemical energy is provided to car as input, in form of fuel. Therefore,

Input = Chemical Potential Energy = 1000 J

Desired Output = Kinetic Energy = 300 J

Therefore,

Efficiency = (300 J/1000 J) * 100%

<u>Efficiency = 30% = 0.3</u>

4 0
3 years ago
Other questions:
  • Two identical satellites are in orbit about the earth. One orbit has a radius r and the other 2r. The centripetal force on the s
    5·1 answer
  • An electron in a region where there is an electric field experiences a force of magnitude 3.8 10-16 n. what is the magnitude of
    5·1 answer
  • Please help .. there could be more than one answer to this question.
    13·1 answer
  • Please I really need help on this
    13·2 answers
  • True or False: In y=mx + b, the y-intercept is given by the value of m.
    11·1 answer
  • Nancy drives her car with a constant speed of 28 miles per hour. how far can she travel in 4 hours?
    6·1 answer
  • A uniform magnetic field of 0.50 T is directed along the positive x axis. A proton moving with a speed of 60 km s enters this fi
    11·1 answer
  • Charge q is 1 unit of distance away from the source charge S. Charge p is six times further away. The force exerted
    7·1 answer
  • Carly rode her bike for 300 meters in 30 seconds. One can calculate her​
    9·1 answer
  • Four electrons are located at the corners of a square 10.0 nm on a side, with an alpha particle at its midpoint.
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!