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
denpristay [2]
3 years ago
13

Two automobiles are equipped with the same singlefrequency horn. When one is at rest and the other is moving toward the first at

20 m/s , the driver at rest hears a beat frequency of 9.0 Hz.
Requried:
What is the frequency the horns emit?
Physics
1 answer:
Kamila [148]3 years ago
8 0

Answer: f ≈ 8.5Hz

Explanation: The phenomenon known as <u>Doppler</u> <u>Shift</u> is characterized as a change in frequency when one observer is stationary and the source emitting the frequency is moving or when both observer and source are moving.

For a source moving and a stationary observer, to determine the frequency:

f_{0} = f_{s}.\frac{c}{c-v_{s}}

where:

f_{0} is frequency of observer;

f_{s} is frequency of source;

c is the constant speed of sound c = 340m/s;

v_{s} is velocity of source;

Rearraging for frequency of source:

f_{0} = f_{s}.\frac{c}{c-v_{s}}

f_{s} = f_{0}.\frac{c-v_{s}}{c}

Replacing and calculating:

f_{s} = 9.(\frac{340-20}{340})

f_{s} = 9.(0.9412)

f_{s} = 8.5

<u>Frequency the horns emit is 8.5Hz.</u>

You might be interested in
An automobile engine delivers 47.4 hp. how much time will it take for the engine to do 6.82 × 105 j of work? one horsepower is e
kogti [31]
1 horsepower is equal to 746 W, so the power of the engine is
P=47.4 hp \cdot 746  \frac{W}{hp}=35360 W
The power is also defined as the energy E per unit of time t:
P= \frac{E}{t}
Where the energy corresponds to the work done by the engine, which is E=6.82 \cdot 10^5 J. Re-arranging the formula, we can calculate the time t needed to do this amount of work:
t =  \frac{E}{P}= \frac{6.82 \cdot 10^5 J}{35360 W}=19.3 s
8 0
3 years ago
What causes earthquakes,tsunami, and volcanic eruptions to happen certain places and not others
Dafna11 [192]
These are all caused by tectonic plate movements. Some areas of the globe are more susceptible to these disasters because they are on or near a fault line where the Earth’s tectonic plates rub against one another, slip beside and under each other, or collide. The places near fault lines are more likely to see earthquakes, tsunamis, and volcanic activity.
5 0
4 years ago
Which type of current flows inside the flashlight A direct B alternating C repeating D pulsating
anzhelika [568]

The flashlight is powered by one or more batteries.
Batteries supply Direct current (DC) .

7 0
3 years ago
Read 2 more answers
Explain how neurons convey information using both electrical and chemical signals.
8090 [49]

Answer:

Explanation:

Neurons communicate via both electrical signals and chemical signals. The electrical signals are action potentials, which transmit the information from one of a neuron to the other; the chemical signals are neurotransmitters, which transmit the information from one neuron to the next.

The electrical signal travels down the axon to the axon terminals where it tells the vesicles to release the neurotransmitters into the synaptic cleft which travel to the receptors of the receiving cell which releases the second messengers

6 0
3 years ago
Una bola de acero rueda y cae por el borde de una mesa desde 4ft por encima del piso. Si golpea el suelo a 5ft de la base de la
ycow [4]

Answer:

     \large\boxed{\large\boxed{10ft/s}}

Explanation:

The question, translated, is:

  • <em>A steel ball rolls and falls off the edge of a table from 4ft above the floor. If you hit the ground 5ft from the base of the table, what was your initial horizontal velocity?</em>

<em />

<h2>Solution</h2>

<em />

This is a projectile motion, for which, the equations that you will need are:

    V_x_0= V_x=x\cdot t

     y=y_0+Vy_o\cdot t-g\cdot t^2/2

<u />

<u>1. Calculate the time that it takes the ball to fall 4ft</u>

    0=4ft-g\cdot t^2/2\\\\t^2=2\times 4ft/( 32.174ft/s^2)=0.24865s^2\\\\t=0.4986s

<u />

<u>2. Calculate the horizontal velocity:</u>

     V_x_0= V_x=x\cdot t\\\\V_x_0=5ft/0.4986s=10.027ft/s\approx 10ft/s

3 0
4 years ago
Other questions:
  • Why is Earth’s North Pole a geographic north pole but a south seeking pole magnetically?
    6·1 answer
  • Ampres law is often written contourintegral B vector (r vector) middot dl vector = mu_0I_enclosed. The integral on the left is
    15·1 answer
  • The magnitude of the weight of a 3.0 kg object on the surface of the earth is 29 N. True False
    13·1 answer
  • Imagine a glass box that is completely sealed and in that box is a cactus in a small pot which statement is most accurate?
    5·2 answers
  • The strength of the electric field at a certain distance from a point charge is represented by E. What is the strength of the el
    6·1 answer
  • Tidal Forces near a Black Hole. An astronaut inside a spacecraft, which protects her from harmful radiation, is orbiting a black
    6·1 answer
  • Complete this equation that represents the process of nuclear fusion. Superscript 226 Subscript 88 Baseline R a yields Superscri
    10·2 answers
  • The current in a coil with a self inductance of 1.5 mH increases from 0 to 1.0 A in a tenth of a second. What is the induced emf
    8·1 answer
  • Using an elastic cord, the astronaut in the black shirt pulls the astronaut with the red shirt back towards him before releasing
    6·1 answer
  • Intelligence test. If you get it right ,you are a critical thinker. You were in the garden,there are 34 people in the yard. You
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!