answer.
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
OLga [1]
2 years ago
6

You are driving along a highway at 35.0 m/s when you hear the siren of a police car approaching you from behind and you perceive

the frequency as 1370 Hz. You are relieved that he is in pursuit of a different speeder when he continues past you, but now you perceive the frequency as 1330 Hz. What is the speed of the police car? The speed of sound in air is 343 m/s.
Physics
1 answer:
swat322 years ago
6 0

Answer:

Explanation:

Given

Apparent  frequency f'=1370\ Hz

Velocity of sound v=343\ m/s

speed of observer v_o=35\ m/s

Using Doppler effect Apparent frequency when source is approaching is given by

f'=f(\frac{v-v_0}{v-v_s})

1370=f(\frac{343-35}{343-v_s})---1

Apparent frequency when source moves away from observer

f''=f(\frac{v+v_0}{v+v_s})

1330=f(\frac{343+35}{343+v_s})---2

Divide 1 and 2 we get

\frac{f'}{f''}=\frac{\frac{343-35}{343-v_s}}{\frac{343+35}{343+v_s}}

\frac{1370}{1330}=\frac{343-35}{343-v_s}\times \frac{343+v_s}{343+35}

v_s=40\ m/s

Thus speed of sound of police car is 40 m/s

You might be interested in
A force Fof 40000 lbf is applied to rod AC the negative Y-direction. The rod is 1000 inches tall. A Force P of 25 lbf is applied
erastova [34]

Answer:

The answer is "effective stress at point B is 7382 ksi "

Explanation:

Calculating the value of Compressive Axial Stress:

\to \sigma y  =\frac{F}{A} = \frac{4 F}{( p d ^2 )} = \frac{(4 x ( - 40000 \ lbf))}{[ p \times (1 \ in)^2 ]} = - 50.9 \ ksi \\

Calculating Shear Transverse:

\to \frac{4v}{ 3 A} = \frac{4 (75 \ lbf + 25 \ lbf)}{ \frac{3 ( lni)^2}{4}}

        = \frac{4 (100 \ lbf)}{ \frac{3 ( lni)^2}{4}} \\\\ = \frac{400 \ lbf)}{ \frac{3 ( lni)^2}{4}} \\\\= 0.17 \ ksi

= R \times 200 \ in - P \times 100 \ in = 12500 \ lbf \times\  in

\to \sigma' =[ s y^2 +3( t \times y^2 + t yz^2 )] \times \frac{1}{2}\\\\

       = [ (-50.9)^2 +3((63.7)^2 +(0.17)^2 )] \times \frac{1}{2}\\\\=[2590.81+ 3(4057.69)+0.0289]\times \frac{1}{2}\\\\=[2590.81+12,173.07+0.0289] \times \frac{1}{2}\\\\=14763.9089\times \frac{1}{2}\\\\ = 7381.95445 \ ksi\\\\ = 7382 \ ksi

8 0
2 years ago
An electron and a proton, starting from rest, are accelerated through an electric potential difference of the same magnitude. in
Yakvenalex [24]
The charges are the same in absolute value, so the change of potential energy is the same. That means that the change in kinetic energy is also the same. Then:

1 = Ke/Kp = m_e *v_e^2 / m_p * v_p^2, or

v_e/v_p = sqrt( m_p/m_e),

So the speed of the electron will be sqrt( m_p/m_e) times greater than the speed of the proton
4 0
2 years ago
A ball is thrown forward at 5 m/s. How would the path of the ball differ on Earth than on the moon? The ball would follow a curv
Kobotan [32]

Answer:

c

Explanation:

.

4 0
2 years ago
Read 2 more answers
hockey puck slides across the ice with an initial velocity of 7.2 m/s. It has a deceleration of 1.1 m/s2 and is traveling toward
dimulka [17.4K]

For this use the formula:

d = Vo * t - (at^2) / 2

Clearing t:

t = d/(v + 0.5*a)

Replacing:

t = 5 m / (7.2 m/s + 0.5 * (-1.1 m/s²)

Resolving:

t = 5 m / (7.2 m/s + (-0.55 m/s²)

t = 5 m / 6.65 m/s

t = 0.75 s

Result:

The time will be <u>0.75 seconds.</u>

7 0
2 years ago
Read 2 more answers
KFC has engineered chickens that do not have beaks and double breast
True [87]
I don't think so.

Before I can accept that rumor, I'll need to see the signed testimony of
two reputable adult witnesses, who have no connection to any business
that profits in any way from the production, sale, or consumption of food,
and who will swear in a public meeting, presided over by three respected
members of their community, that they personally saw more than one of
the alleged beakless double-breasted chickens in the same place at the
same time.

A photo is not acceptable ... not for me, and not for the two witnesses.
6 0
2 years ago
Other questions:
  • A scientist measures the growth of a bamboo plant over time. The table below shows the results.
    5·2 answers
  • Two negative charges that are both -0.3C push each other apart with a force of 19.2 N. How far apart are the two charges?
    15·1 answer
  • A tennis player who is recovering from an ankle injury and is not allowed to change directions can maintain her cardio fitness l
    12·2 answers
  • You use energy to heat your home. what ultimately happens to the energy that you pay for in your heating bill?
    14·2 answers
  • Consider the static equilibrium diagram here. What is the angle F1 must make with the horizontal?
    13·2 answers
  • What is a manifest function of a married father joining the military
    9·2 answers
  • You are a member of an alpine rescue team and must get a box of supplies, with mass 2.20 kg , up an incline of constant slope an
    12·1 answer
  • a 75 kg man is standing at rest on ice while holding a 4kg ball. if the man throws the ball at a velocity of 3.50 m/s forward, w
    10·1 answer
  • Reginald slipped and broke his leg in his kitchen when he ran inside to grab a cookie. His mother had just mopped the floor. Wha
    15·1 answer
  • Where is there kinetic energy in this system?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!