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
san4es73 [151]
3 years ago
13

Help me please I need help?

Physics
1 answer:
sweet [91]3 years ago
4 0
Your answer is c. homologous structures
You might be interested in
A person, with his ear to the ground, sees a huge stone strike the concrete pavement. A moment later two sounds are heard from t
marishachu [46]

Answer:

The impact occured at a distance of 2478.585 meters from the person.

Explanation:

(After some research on web, we conclude that problem is not incomplete) The element "Part A" may lead to the false idea that question is incomplete. Correct form is presented below:

<em>A person, with his ear to the ground, sees a huge stone strike the concrete pavement. A moment later two sounds are heard from the impact: one travels in the air and the other in the concrete, and they are 6.4 seconds apart. How far away did the impact occur? (Sound speed in the air: 343 meters per second, sound speed in concrete: 3000 meters per second)</em>

Sound is a manifestation of mechanical waves, which needs a medium to propagate themselves. Depending on the material, sound will take more or less time to travel a given distance. From statement, we know this time difference between air and concrete (\Delta t), in seconds:

\Delta t = t_{A}-t_{C} (1)

Where:

t_{C} - Time spent by the sound in concrete, in seconds.

t_{A} - Time spent by the sound in the air, in seconds.

By suposing that sound travels the same distance and at constant speed in both materials, we have the following expression:

\Delta t = \frac{x}{v_{A}}-\frac{x}{v_{C}}

\Delta t = x\cdot \left(\frac{1}{v_{A}}-\frac{1}{v_{C}}  \right)

x = \frac{\Delta t}{\frac{1}{v_{A}}-\frac{1}{v_{C}}  } (2)

Where:

v_{C} - Speed of the sound in concrete, in meters per second.

v_{A} - Speed of the sound in the air, in meters per second.

x - Distance traveled by the sound, in meters.

If we know that \Delta t = 6.4\,s, v_{C} = 3000\,\frac{m}{s} and v_{A} = 343\,\frac{m}{s}, then the distance travelled by the sound is:

x = \frac{\Delta t}{\frac{1}{v_{A}}-\frac{1}{v_{C}}  }

x = 2478.585\,m

The impact occured at a distance of 2478.585 meters from the person.

7 0
3 years ago
When humans look at the sky, it appears blue, but the Sun appears yellow. What causes this phenomenon?
Lesechka [4]
I believe that the answer is <span>C. The atmosphere scatters blue light more than yellow light.</span>
8 0
3 years ago
Read 2 more answers
Two identical balls move directly toward each other with equal speeds. how will the balls move if they collide and stick togethe
Citrus2011 [14]
The momentum of both the identical balls would eventually be transferred to one another when it comes to a point wherein they will collide. In addition, the phenomenon is called an elastic collision wherein both the momentum and energy of the system would considered to be conserved.
7 0
3 years ago
A high power line carries a current of 1.0 kA. What is the strength of the magnetic field this line produces at the ground, 10 m
solmaris [256]

Answer:

The strength of the magnetic field that the line produces is 2x10^{-5} Tesla.

Explanation:

From Biot-Savart law, the equation to determine the strength of the magnetic field for any straight wire can be deduced:

           

B = \frac{\mu_{0}I}{2\pi r} (1)      

                                     

Where \mu_{0} is the permiability constant, I is the current and r is the distance from the wire.    

             

Notice that it is necessary to express the current, I, from kiloampere to ampere.

I = 1.0kA \cdot \frac{1000A}{1kA} ⇒ 1000A

Finally, equation 1 can be used:

B = \frac{(4\pi x10^{-7}T.m/A)(1000A)}{2\pi (10m)}    

           

B = 2x10^{-5}T    

Hence, the strength of the magnetic field that the line produces is 2x10^{-5} Tesla.

         

8 0
3 years ago
A rectangular piece of​ cardboard, whose area is 352 square​ centimeters, is made into an open box by cutting a 2​-centimeter sq
Usimov [2.4K]

Answer:

Dimension of cardboard is 22 m by 16 m

Explanation:

Given that,

Area = 352 cm²

Side of each square cutting from corner = 2 cm

Volume of box = 432 cm³

Let the two sides are x and y.

The area of the rectangular piece is

xy=352

y=\dfrac{352}{x} -------- (1)

The volume of the rectangular piece

2(x-4)(\dfrac{352}{x}-4)=432

x^2-38x+352=0

(x-16)(x-22)=0

x=16,22

Put the value of x in the equation (I)

For x = 16

y=\dfrac{352}{16}=22

For x = 22

y=\dfrac{352}{22}=16

Dimension of cardboard is 22 m by 16 m

8 0
3 years ago
Other questions:
  • What is the power output of an electric motor that lifts a 2.0 kilogram block 15 meters vertically in 6.0 seconds
    5·1 answer
  • Which best describes the differences between a resume and a CV?
    9·1 answer
  • A material is said to be ductile if it
    13·1 answer
  • What's the hikers average velocity during part D of the hike?
    7·1 answer
  • A reducing elbow in a horizontal pipe is used to deflect water flow by an angle θ = 45° from the flow direction while accelerati
    7·1 answer
  • Can someone please help me with this problem?
    6·1 answer
  • If two waves are traveling at the same speed, which statement will be true about their wavelengths? 1.The wave with higher frequ
    11·1 answer
  • A 75.0-kg person is riding in a car moving at 20.0 m/s when the car runs into a bridge abutment. (a) calculate the average force
    5·1 answer
  • A disk has 128 tracks of 32 sectors each, on each surface of eight platters. The disk spins at 3600 RPM and takes 15 ms to move
    9·1 answer
  • A camera lens used for taking close-up photographs has a focal length of 22.0 mm. The farthest it can be placed from the film is
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!