Physics, 05.03.2021 05:30 gransazer863

You are in a car traveling at 20 m/s. An ambulance is behind you traveling 35 m/s in the same direction. What frequency do you hear if the siren has a frequency of 550 Hz?

Answers: 2

Show answers

Answers

Answer from: trevorhenyan51

The frequency heard is 576.78 Hz

Explanation:

The Doppler effect is defined as the apparent frequency change of a wave produced by the relative movement of the source with respect to its observer. In other words, this effect is the change in the perceived frequency of any wave motion when the sender and receiver, or observer, move relative to each other.

This is what happens in the first part of this problem, where the sender is train A and the receiver is train B. They are both moving in opposite directions. In this case, where both are in motion, the frequency perceived by the receiver will increase when receiver and transmitter increase their separation distance and will decrease whenever the separation distance between them is reduced. The following expression is considered the general case of the Doppler effect:

$f'=f*\frac{v+-vR}{v+-vE}$

Where:

f ', f: Frequency perceived by the receiver and frequency emitted by the issuer respectively. Its unit of measurement in the International System (S.I.) is the hertz (Hz), which is the inverse unit of the second (1 Hz = 1 s-1)

v: Velocity of propagation of the wave in the medium. It is constant and depends on the characteristics of the medium. In this case, the speed of sound in air is considered to be 343 m / s

vR, vE: Speed of the receiver and the emitter respectively. Its unit of measure in the S.I. is the m / s

±, ∓:

We will use the + sign:

In the numerator if the receiver approaches the emitter In the denominator if the emitter moves away from the receiver

We will use the sign -:

In the numerator if the receiver moves away from the emitter In the denominator if the emitter approaches the receiver

In this case you are in a car traveling at 20 m/s and an ambulance is behind you traveling 35 m/s in the same direction.

In this case the receiver, you in the car, moves away from the emitter, while the emitter, the ambulance, approaches the receiver behind you in the same direction. So the frequency is calculated by the expression:

$f'=f*\frac{v-vR}{v-vE}$

Being:

f= 550 Hzv=343 m/svR= 20 m/svE= 35 m/s

and replacing:

$f'=550 Hz*\frac{343 m/s-20 m/s}{343 m/s-35 m/s}$

you get:

f'= 576.78 Hz

The frequency heard is 576.78 Hz

Answer from: Quest

ya te mando la respuesta

Answer from: Quest

the answer is the first electromagnet (a). this is because it has more coils around the ferromagnetic material. increasing the number of coils increases the surface area in which the metal interacts with the current in the coil. this enables more atoms in the metal to become aligned hence becoming more magnetized.

Another question on Physics

Physics, 22.06.2019 08:00

5g of ammonium nitrate was dissolved in 60g of water in an insulated container. the temperature at the start of the reaction was 23.0°c and at the end it was 19.0°c. calculate the energy absorbed by the reaction.

Answers: 3

Answer

Physics, 22.06.2019 13:10

The bar of prob. 5/82 is repeated here. the ends of the 0.4-m bar remain in contact with their re- spective support surfaces. end b has a velocity of 0.5 m/s and an acceleration of 0.3 m/s2 in the di- rections shown. determine the angular accelera- tion of the bar and the acceleration of end a.

Answers: 3

Answer

Physics, 22.06.2019 21:10

For the below questions, consider a consumer that consumes two goods, x and z with the following utility function. u with bar on top space equals space x to the power of 1 third end exponent z to the power of 2 over 3 end exponent suppose initial values for income and the prices of goods x and z are y equals 90, p subscript x equals space 10, and p subscript z equals 15 respectively, then the price of good x falls to syntax error from line 1 column 89 to line 1 column 100. unexpected '\'.. what is the magnitude of the total effect

Answers: 3

Answer

Physics, 22.06.2019 21:10

Select the best definition for wavelength. the height of an oscillating electromagnetic wave the rate at which electromagnetic waves oscillate. the distance between two crests of an electromagnetic wave. the oscillations of electric and magnetic fields select the best definition for frequency. the oscillations of electric and magnetic fields. the height of an oscillating electromagnetic wave. the distance between two crests of an electromagnetic wave. the rate at which electromagnetic waves oscillate

Answers: 1

Answer

You know the right answer?

You are in a car traveling at 20 m/s. An ambulance is behind you traveling 35 m/s in the same direct...

Questions