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
Gnoma [55]
2 years ago
10

A train is traveling west at a velocity of 25 m/s. Another train is traveling east directly toward the west-bound train at a vel

ocity of 15 m/s. The west-bound train blows its whistle with a frequency of 600 Hz when the two trains are 1000 m apart and then blows its whistle again 10 seconds later. For passengers on the east-bound train, how will the perceived frequency of the first whistle compare with the perceived frequency of the second whistle
Physics
1 answer:
dusya [7]2 years ago
4 0

(a) The frequency observed by the passenger on the east-bound train when they are 1000 m apart is 675.5 Hz.

(b) After 10 seconds, the frequency observed by the passenger on the east-bound train will be greater than the frequency observed when they are 1000 m apart.

<h3>Observed frequency</h3>

The frequency observed by the passenger on east-bound train is calculated by applying Doppler shift formula.

f = f_0(\frac{v \pm v_0}{v\pm v_s} )

where;

  • f is observed frequency
  • f₀ is original frequency or source frequency
  • v is speed of sound
  • v₀ is speed of observer (positive when moving towards source)
  • vs is source frequency (negative when moving towards observer)

<h3>when the two trains are 1000 m apart</h3>

f = 600(\frac{343 +15}{343-25} )\\\\f = 675.5 \ Hz

The frequency observed by the passenger increases with decrease in distance between the two trains.

Thus, after 10 seconds, the frequency observed by the passenger on the east-bound train will be greater than the frequency observed when they are 1000 m apart.

Learn more about Doppler shift here: brainly.com/question/23841569

#SPJ1

You might be interested in
Two cars, initially at rest and 5 km apart at t=0 , simultaneously move toward each other. Car A travels at a constant speed of
Anastasy [175]

Answer:

<em>d. 268 s</em>

Explanation:

<u>Constant Speed Motion</u>

An object is said to travel at constant speed if the ratio of the distance traveled by the time taken is constant.

Expressed in a simple equation, we have:

\displaystyle v=\frac{d}{t}

Where  

v = Speed of the object

d = Distance traveled

t  = Time taken to travel d.

From the equation above, we can solve for d:

d = v . t

And we can also solve it for t:

\displaystyle t=\frac{d}{v}

Two cars are initially separated by 5 km are approaching each other at relative speeds of 55 km/h and 12 km/h respectively. The total speed at which they are approaching is 55+12 = 67 km/h.

The time it will take for them to meet is:

\displaystyle t=\frac{5}{67}

t = 0.0746 hours

Converting to seconds: 0.0746*3600 = 268.56

The closest answer is d. 268 s

8 0
3 years ago
An object of mass 4kg is moving along a horizontal plane. If the coefficient of kinetic friction is 0.2 find the friction force
lana66690 [7]

Answer:

The friction force acting on the object is 7.84 N

Explanation:

Given;

mass of object, m = 4 kg

coefficient of kinetic friction, μk = 0.2

The friction force acting on the object is calculated as;

F = μkN

F = μkmg

where;

F is the frictional force

m is the mass of the object

g is the acceleration due to gravity

F = 0.2 x 4 x 9.8

F = 7.84 N

Therefore, the friction force acting on the object is 7.84 N

5 0
3 years ago
There is a puncture in the inner tor of your bicycle. Give a method to detect the position of the puncture
Pani-rosa [81]

Answer:

Explanation:

The first method to engage is to listen to where the sound of air in the inner Tor escaping originated and look to see if u can find it. You can then feel the escape air with your hand.

You can Put it inside a container of water and see the bubble and rotate the inner tube to pass all of it through the water

7 0
3 years ago
Suppose that a steel bridge, 1000 m long, were built without any expansion joints. Suppose that only one end of the bridge was h
Stels [109]

Answer:

The difference in the length of the bridge is 0.42 m.

Explanation:

Given that,

Length = 1000 m

Winter temperature = 0°C

Summer temperature = 40°C

Coefficient of thermal expansion \alpha= 10.5\times10^{-6}\ K^{-1}

We need to calculate the difference in the length of the bridge

Using formula of the difference in the length

\Delta L=L\alpha\Delta T

Where, \Delta T= temperature difference

\alpha=Coefficient of thermal expansion

L= length

Put the value into the formula

\Delta L=1000\times10.5\times10^{-6}(40^{\circ}-0^{\circ})

\Delta L=0.42\ m

Hence, The difference in the length of the bridge is 0.42 m.

5 0
3 years ago
Con base en el tema ley de ohm, resistividad y resistencia resuelva los siguientes
Bumek [7]
Answer:Explanation:gfgfgfgfgfgfgfgfgfg
3 0
2 years ago
Other questions:
  • If the potential across two parallel plates, separated by 9.0 cm, is 12 volts, what is the electric field strength in volts per
    5·1 answer
  • Describing Changes of State
    8·1 answer
  • A cylinder shaped jar has a radius of 2 cm and a hight of 6 cm what the volume of the jar
    12·1 answer
  • If an element has 7 valence electrons, how many dots will be in the elements dot diagram
    9·1 answer
  • The Whirlpool galaxy is about 30 million light-years away. If you were in a spaceship that could travel at half of the speed of
    15·1 answer
  • A nylon thread is subjected to a 8.5-N tension force. Knowing that E 5 3.3 GPa and that the length of the thread increases by 1.
    9·1 answer
  • Find the magnitude and direction for 101m,60.0,85.0m
    13·1 answer
  • Suppose that the voltage across the resistor is held constant at 40 volts. If the resistance is steadily decreasing at a rate of
    14·1 answer
  • What happens to an object's gravitational potential energy as it falls from some height?​
    12·1 answer
  • Following your push the ball rolls down the lane at 4.2m/s. What is the net force on the ball as it rolls down the lane at the c
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!