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
slava [35]
3 years ago
12

A certain wire has a length l and a resistance r. It is stretched uniformly to a length of 2l. The resistance of the wire after

it has been stretched is
Physics
1 answer:
skelet666 [1.2K]3 years ago
8 0

I am not sure whether this is the right way to go about answering the question.

The resistance of a wire is proportional to its length, therefore doubling the length should double the resistance. But resistance is also proportional to the inverse square of the wire's cross-sectional area, and stretching the wire seems to imply increasing its length and decreasing its cross-sectional area, which would increase the resistance more than simply increasing its length.

I'll just say to only care about the effect of increasing the wire's length. Due to the wire's length now being 2l, the new resistance is 2r.

You might be interested in
Benny has 20 jellybeans and wants to share with his friends how many will each friend get? there are 5 friends.
trasher [3.6K]

Answer each friend will get 3.33333 repeating if he is included. if only his friends are getting them then each one gets 4

Explanation:

devide 20/6 and 20/5 respectively.

7 0
3 years ago
Using Rayleigh's criterion, calculate the diameter of an earth-based telescope that gives this resolution with 700 nm light.
pogonyaev

Complete Question

Due to blurring caused by atmospheric distortion, the best resolution that can be obtained by a normal, earth-based, visible-light telescope is about 0.3 arcsecond (there are 60 arcminutes in a degree and 60 arcseconds in an arcminute).Using Rayleigh's criterion, calculate the diameter of an earth-based telescope that gives this resolution with 700 nm light

Answer:

The diameter is  D = 0.59 \  m    

Explanation:

From the question we are told that

      The best resolution is  \theta  =  0.3 \  arcsecond

       The  wavelength is  \lambda  =  700 \  nm =  700 *10^{-9 } \  m

       

Generally the

         1 arcminute  = >  60 arcseconds

=>      x arcminute =>   0.3 arcsecond

So

       x =  \frac{0.3}{60 }

=>    x = 0.005 \  arcminutes

Now

         60 arcminutes  =>  1 degree

          0.005 arcminutes = >  z degrees  

=>       z =  \frac{0.005}{60 }

=>      z =  8.333 *10^{-5}  \ degree

Converting to radian  

           \theta  = z =  8.333 *10^{-5}  * 0.01745 = 1.454 *10^{-6} \  radian

Generally the resolution is mathematically represented as

            \theta  =  \frac{1.22 *  \lambda  }{ D}

=>    D =  \frac{1.22 * \lambda }{\theta }

=>     D =  \frac{1.22 * 700 *10^{-9} }{ 1.454 *10^{-6} }    

=>     D = 0.59 \  m    

4 0
3 years ago
Today’s scientist must search through scientific journals before performing an experiment with making methodical observations wh
Natalija [7]

Answer:

in the lab

Explanation:

cause that is where scientist spend their time doing research ...

4 0
3 years ago
A double-slit experiment yields an interference pattern due to the path length difference from light traveling through one slit
Lapatulllka [165]

Answer:

Therefore the correct statement is B.

Explanation:

In the interference and diffraction phenomena, the natural wave of electromagnetic radiation must be taken into account, the wave front that advances towards the slit can be considered as when it reaches it behaves like a series of wave emitters, each slightly out of phase from the previous one, following the Huygens principle that states that each point is compiled as a source of secondary waves.

The sum of all these waves results in the diffraction curve of the slit that has the shape

      I = Io sin² θ /θ²

Where the angle is a function of the wavelength and the width of the slit.

From the above, the interference phenomenon can be treated as the sum of two diffraction phenomena displaced a distance equal to the separation of the slits (d)

Therefore the correct statement is B

6 0
3 years ago
Two long, straight wires are parallel and 20 cm apart. One carries a current of 2.2 A, the other a current of 5.9 A. (a) If the
Leya [2.2K]

Answer: 1.298\times 10^{-5}\ N/m

Explanation:

Given

Current in the first wire I_1=2.2\ A

Current in the second wire I_2=5.9\ A

wires are 20\ cm apart

Force per unit length between the current-carrying wires is

\Rightarrow \dfrac{F}{l}=\dfrac{\mu_oI_1I_2}{2\pi r}

Force exerted  by the wires is the same

Put the values

\Rightarrow \frac{F}{l}=f=\dfrac{4\pi \times 10^{-7}\times 2.2\times 5.9}{2\pi \times 0.2}=1.298\times 10^{-5}\ N/m

This force will be repulsive in nature as the current is flowing opposite

4 0
3 years ago
Other questions:
  • ILL RATE YOU A 5, THANK YOU, AND MARK YOU AS BRAINLIEST! HURRY!
    13·2 answers
  • Why is it impossible to "defy gravity“?
    8·1 answer
  • S= 1/2(V f + V I )t solve for V f <br><br> show me how
    6·1 answer
  • A rocket sled is tested at "5 g" (5 times the acceleration due to gravity). If the sled starts from rest at position do= 0.00, h
    14·2 answers
  • In what unit do we measure force? in physics​
    5·1 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
  • A student is investigating the differences between light waves and sound waves. The student does this by using a capsule filled
    5·2 answers
  • If you use a 1500 watt sound system for 5 hours a day , calculate the amount of electricity used​
    5·1 answer
  • 3. Two fans blow at 5 ms^-1 in a easterly direction and 8ms^-1 in a Northerly
    6·1 answer
  • A car travels straight for 20 miles on a road that is 30° north of east. What is the east component of the car’s displacement
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!