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
Tema [17]
3 years ago
14

A bird is flying directly toward a stationary bird-watcher and emits a frequency of 1420 Hz. The bird-watcher, however, hears a

frequency of 1456 Hz. What is the speed of the bird, expressed as a percentage of the speed of sound
Physics
1 answer:
kogti [31]3 years ago
7 0

Answer:

2.47 %

Explanation:

We are given;

Frequency emitted by source(bird); f_s = 1420 Hz

Frequency heard by observer; f_o = 1456 Hz

From doppler shift frequency, we know that;

f_o = f_s [c/(c - c_s)]

Where c_s is speed of source which is the bird and c is speed of sound.

Thus;

Rearranging the equation, we have;

f_s/f_o = (c - c_s)/c

f_s/f_o = 1 - (c_s/c)

Plugging in the relevant values to get ;

1420/1456 = 1 - (c_s/c)

0.9753 = 1 - (c_s/c)

1 - 0.9753 = (c_s/c)

(c_s/c) = 0.0247

Since we want it expressed im percentage,

Thus, (c_s/c) % = 0.0247 x 100 = 2.47 %

You might be interested in
A spring attached to the ceiling is stretched 2.45 meters by a four kilogram mass. If the mass is set in motion in a medium that
denpristay [2]

Answer:

d²x/dt² = - 4dx/dt - 4x is the required differential equation.

Explanation:

Since the spring force F = kx where k is the spring constant and x its extension = 2.45 equals the weight of the 4 kg mass,

F = mg

kx = mg

k = mg/x

= 4 kg × 9.8 m/s²/2.45 m

= 39.2 kgm/s²/2.45 m

= 16 N/m

Now the drag force f = 16v where v is the velocity of the mass.

We now write an equation of motion for the forces on the mass. So,

F + f = ma (since both the drag force and spring force are in the same direction)where a = the acceleration of the mass

-kx - 16v = 4a

-16x - 16v = 4a

16x + 16v = -4a

4x + 4v = -a where v = dx/dt and a = d²x/dt²

4x + 4dx/dt = -d²x/dt²

d²x/dt² = - 4dx/dt - 4x which is the required differential equation

6 0
4 years ago
A train travels 1000 m south for 100 s. What is the
Alexandra [31]
C. 10 m/s
You divide 1000 m by 100 s.
1000/100 to find the velocity
5 0
3 years ago
In a crash or collision, why is it advantageous for an occupant to extend the time during which the collision is taking place?
Veseljchak [2.6K]

Answer:

Explanation:

During a car collision momentum of vehicle ceases within a fraction of seconds so Force due to the impulse is huge.

Impulse is defined as the product of average force and time. If we can increase the period of collision for the same impulse then the average force imparted will be less.

If we can increase the time period then damage due to collision will be less.

                     

3 0
3 years ago
A stone is dropped from a cliff and falls 9.44 meters. What is the speed of the stone when it reaches the ground?
Lunna [17]

Answer:

option A

Explanation:

given,                                              

height of the drop of stone = 9.44 m

speed of the stone = ?                          

As the stone is dropped the energy of the stone will be conserved.

using conservation of energy.            

Potential energy = Kinetic energy    

m g h = \dfrac{1}{2} m v^2  

     v = \sqrt{2gh}                  

     v = \sqrt{2\times 9.8 \times 9.44}

     v = \sqrt{185.024}              

            v = 13.60 m/s                      

Hence, the correct answer is option A

3 0
3 years ago
When students work in a chemistry lab, the location of which items would be the most important for each student to know?
irina [24]
The safety items such as eye washing station, fire blanket, and the class shower.
6 0
3 years ago
Other questions:
  • Choose all that apply.
    5·2 answers
  • What is Metabolism?
    7·1 answer
  • If the x-component of a vector is 17, and the angle between the vector and the x-axis is 46 degrees, what is the magnitude of th
    14·2 answers
  • What did it mean if something was in blue glass?
    9·1 answer
  • Example of the word médium ?
    12·1 answer
  • Kepler's first law states that planets orbit the Sun in a path called a(n)
    5·2 answers
  • TP2 2) An example of a 3rd gen lever is:
    10·1 answer
  • A uniform electric field exists in the region between two oppositely charged plane-parallel plates. An electron is released from
    7·1 answer
  • An object with a height of 1.0 cm is placed 1.4 cm from a convex lens that has a
    10·1 answer
  • A scalar quantity has
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!