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
what is the acceleration of an object that moves at a constant velocity of 2.0 meters per second for 5 seconds?
nexus9112 [7]
Constant velocity means moving in a straight line at a speed that doesn't change. If the object is moving with constant velocity then its acceleration is zero. Acceleration is the rate at which velocity is changing.
3 0
3 years ago
Assuming that each nucleus is roughlyspherical and that its mass is roughly equal to A (in atomic mass units {\rm u}), what is t
lara [203]

Answer:

ρ/ρ2 = 3 / R₀       the two densities are different

Explanation:

Density is defined as

       ρ = M / V

As the nucleus is spherical

       V = 4/3 π r³

Let's replace

      ρ = A / (4/3 π R₀³)

      ρ = ¾ A / π R₀³

b)

      ρ2 = F / area

The area of ​​a sphere is

     A = 4π R₀²

     ρ2 = F / 4π R₀²

     ρ2 = F / 4π R₀²

Atomic number is the number of protons in the nucleon in not very heavy nuclei. This number is equal to the number of neutrons, but changes in heavier nuclei, there are more neutrons than protons.

Let's look for the relationship of the two densities

     ρ/ρ2 = ¾ A / π R₀³ / (F / 4π R₀²)

     ρ /ρ2 = 3 (A / F) (1 / R₀)

In this case it does not say that the nucleon number is A (F = A), the relationship is

     ρ/ρ2 = 3 / R₀

I see that the two densities are different

3 0
3 years ago
A pilot drops a bomb from a plane flying horizontally with constant velocity. When the bomb hits the ground, the horizontal loca
polet [3.4K]

Answer: The horizontal location of the plane will BE OVER THE BOMB

Explanation:

As soon as the bomb was dropped, the bomb will fall under gravity (free fall) and the location of the plane continues to increase horizontally till the bomb reaches the ground which is a falling distance to be travelled by the bomb at 9.8m/s²

8 0
3 years ago
A transformer is to be used to provide power for a computer disk drive that needs 6.0 V (rms) instead of the 120 V (rms) from th
Ipatiy [6.2K]

Answer:

N_{2}=20 turns

Explanation:

The given case is a step down transformer as we need to reduce 120 V to 6 V.

number of turns on primary coil N_{P}= 400

current delivered by  secondary coil  I_{S}= 500 mA

output voltage = 6 V (rms)

we know that

I_{p}=\frac{V_{out}}{V_{in}\times I_{s}}

putting values we get

I_{p}=\frac{6}{120\times 0.5}

I_{p}= 0.1 A

to calculate number of turns in secondary

\frac{N_{2}}{400} =\frac{6}{120}

therefore, N_{2}=20 turns

5 0
3 years ago
Pls helpppppp i’ll give brainliest
Tema [17]

Answer:

D

Explanation:

The answer is Niels Bohr's planetary model, the difference between this model and all of the other models is that the Bohr's PM Is more of layers of

Nucleus - Protons and Neutrons

Electron Orbital - Period 1 Elements

2 electrons

Electron Orbital - Period 2 Elements

8 electrons

Electron Orbital - Period 3 Elements

8 electrons

If that made sense-

3 0
2 years ago
Read 2 more answers
Other questions:
  • Will the current increase or decrease if you increase voltage?
    13·1 answer
  • A merry-go-round consists of a uniform solid disc of 225kg and a radius of 6.0m. A single 80kg person stands on the edge when it
    11·1 answer
  • How far (in meters) will you travel in 3 minutes running at a rate of 6 m/s?
    11·1 answer
  • How frequently do most coastal areas experience high tides?
    10·1 answer
  • SOMEONE PLEASE ANSWER IM DESPRATE AND NOONES ANSWERING MY QUESTIONS, ILL GIVE U A PICTURE OF MY CAT TO BRIGHTEN YOUR DAY AND BRA
    15·1 answer
  • A wire 0.50 m long carrying a current of 16.0 A is at right angles to a 0.20 T magnetic field. How strong a force acts on the wi
    11·1 answer
  • Which is heavier: 30 kilogram or 300 milligrams?
    7·1 answer
  • Would you classify petroleum as a renewable or nonrenewable resource? Justify your answer in two or more complete sentences.
    12·1 answer
  • A 2500-kg car is being pushed up a hill at an angle of 35 degrees. Determine the gravitational
    12·1 answer
  • Ice floats on water.​
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!