2. A uniform wire of resistance R is stretched until its length doubles. Assuming its density and resistivity remain constant, what is its new resistance

Answers

Answer 1

Answer:

Resistance is quadrupled.

Explanation:

Solving this requires us to use the formula of resistivity.

Resistivity is usually said to be the measure of the resistance of a particular size of any given material to the electrical conduction. It is mathematically represented as

ρ = RA/L, where

ρ = the resistivity of the given material

R = the resistance of the material

A = the area of the material

L = length of the material.

From the question, we're told that the length is doubled with the resistivity and density remaining constant. If the density is constant, this makes the volume constant as well.

Volume, V = A * L. We're then told that the length is doubled. If the length is doubled, for the volume to remain constant, then the area must be halved.

Volume, V = A/2 * 2L

Making, Resistance R, subject of the formula, we have

R = ρL/A.

Since resistivity is constant and the area is halved, we then have

R = 2L / (1/2A)

R = 4L / A

If the length is doubled, we have the resistance to be quadrupled


Related Questions

A hollow sphere is attached to the end of a uniform rod. The sphere has a radius of 0.64 m and a mass of 0.48 kg. The rod has a length of 1.78 m and a mass of 0.50 kg. The rod is placed on a fulcrum (pivot) at X = 0.34 m from the left end of the rod.
(a) Calculate the moment of inertia (click for graphical table) of the contraption around the fulcrum. kg m2
(b) Calculate the torque about the fulcrum, using CCW as positive. N.m
(c) Calculate the angular acceleration of the contraption, using CCW as positive. rad/s2
(d) Calculate the linear acceleration of the right end of the rod, using up as positive. m/s2

Answers

The image of this hollow sphere and uniform rod is missing, so i have attached it.

Answer:

A) J = 0.7443 kg•m²

B) T = 1.9169 N•m CCW

C) α = 2.5754 rad/s²

D) a = 3.966 m/s²

Explanation:

A) The moment of inertia J of the contraption around the fulcrum is given by the formula;

J = Jℓ + Jr

Let's calculate Jℓ

Jℓ = [((0.34²/3) × 0.50 × 0.34)/1.78] + (0.48 × (0.34 + 0.64)²)

Jℓ = 0.4647 kg•m²

Now, let's Calculate Jr

Jr = ((1.78 - 0.34)²/3) × ((1.78 - 0.34)/1.78) × 0.50

Jr = 0.2796 kg•m²

Thus;

J = 0.4647 + 0.2796

J = 0.7443 kg•m²

(b) Using CCW as positive, Torque in Nm is calculated as;

T = Tℓ - Tr

Let's calculate Tℓ

Tℓ = [(0.48 × (0.64 + 0.34)) + (0.50 × 0.34/1.78) × 0.34/2)] × 9.81

Tℓ = 4.7739 N•m CCW

Now, let's Calculate Tr;

Tr = [(0.50 × (1.78 - 0.34)/1.78) × (1.78 - 0.34)/2)] × 9.81

Tr = 2.857 N•m CW

Thus;

T = 4.7739 - 2.857

T = 1.9169 N•m CCW

(c) The angular acceleration α of the contraption, using CCW is gotten from the formula;

α = T/J

α = 1.9169/0.7443

α = 2.5754 rad/s²

(d) The linear acceleration a of the right end of the rod, using up as positive is given by;

a = α*(1.78 - 0.34)

a = 2.5754 × 1.54

a = 3.966 m/s²

A) the moment of inertia of the contraption is 0.7443 kgm²

B) The torque about the fulcrum is 1.9169 Nm

C) Angular acceleration of the contraption is 2.5754 rad/s²

D) The linear acceleration of the contraption is 3.966 m/s²

Moment of inertia:

(A) The moment of inertia I of the contraption around the fulcrum is given by :

[tex]I = [(0.34^2/3) \times 0.50 \times 0.34)/1.78 + (0.48 \times (0.34 + 0.64)^2)] + [(1.78 - 0.34)^2/3) \times (1.78 - 0.34)/1.78) \times 0.50][/tex]

I = 0.4647 + 0.2796

I = 0.7443 kgm²

(B) Using CCW as positive, Torque in Nm is given by;

T = [(0.48 × (0.64 + 0.34)) + (0.50 × 0.34/1.78) × 0.34/2)] × 9.81 - [(0.50 × (1.78 - 0.34)/1.78) × (1.78 - 0.34)/2)] × 9.81

T = 4.7739 - 2.857

T = 1.9169 Nm

(C) The angular acceleration (α) of the contraption is given by:

α = T/I

since, torque is defined as T = Iα

α = 1.9169/0.7443

α = 2.5754 rad/s²

(D) The linear acceleration (a) of the right end of the rod

a = αr

where r is the distance from the pivot

a = α × (1.78 - 0.34)

a = 2.5754 × 1.54

a = 3.966 m/s²

Learn more about moment of inertia:

https://brainly.com/question/6953943?referrer=searchResults

Do blood cells have a nuclei? Describe the shape of blood platelets.

Answers

Answer: Mature red blood cells don't have nuclei.

Explanation: " Platelets are irregularly shaped, have no nucleus, and typically measure only 2–3 micrometers in diameter. "

Hope this Helps!!

At the base of a hill, a 90 kg cart drives at 13 m/s toward it then lifts off the accelerator pedal). If the cart just barely makes it to the top of this hill and stops, how high must the hill be?

Answers

Answer:

8.45 m

Explanation:

From the question given above, the following data were obtained:

Mass (m) = 90 Kg

Initial velocity (u) = 13 m/s

Final velocity (v) = 0 m/s

Height (h) =?

NOTE: Acceleration due to gravity (g) = 10 m/s²

The height of the hill can be obtained as follow:

v² = u² – 2gh (since the cart is going against gravity)

0² = 13² – (2 × 10 × h)

0 = 169 – 20h

Rearrange

20h = 169

Divide both side by 20

h = 169/20

h = 8.45 m

Therefore, the height of the hill is 8.45 m

A motorcycle is traveling along a highway at 29 m/s. How far does the motorcycle travel in 18 s?

Answers

Answer:

the motorcycle travels 522 miles in 18 seconds Explanation: 29 x 18 is 522 I'm pretty sure that's what it was asking but I don't know

When grip strength increases:

a. action potential voltage increases.
b. action potential frequency decreases.
c. action potential frequency increases.
d. action potential frequency increases.
e. the number of active motor units increases.

Answers

Answer:

e. the number of active motor units increases.

Explanation:

There is a direct relationship between the number of active motor units and the grip strength in a given scenario. For example, increase in the grip strength leads to increase in the number of active motor units. In the other-hand, the decrease in grip strength leads to the decrease in the number of active motor units.

a sharp image is formed when light reflects from a

Answers

Answer:

Regular reflection

Explanation:

Regular reflection occurs when light reflects off a very smooth surface and forms a clear image.

i hope this helps a bit.

According to the context, a sharp image is formed when light reflects from a regular reflection.

What is regular reflection?

It is reflection without diffusion that obeys the laws of geometrical optics, as in mirrors.

This reflection of light happens when the angles that the two rays determine with the surface are equal.

Therefore, we can conclude that according to the context, a sharp image is formed when light reflects from a regular reflection.

Learn more about regular reflection here: https://brainly.com/question/3778324

#SPJ2

3
How does the electrical conductivity of metals
and metalloids change with an increase in
temperature?​

Answers

Answer:

In metals there are free electrons at normal temperature so when we increase temperature it resistivity gets increases,so conductivity decreases,while in semiconductor the electrons are not free so when we increase the temperature the covalent bonds begin to break and the electron becomes free so conductivity get.

Explanation:

A ball rolls along the floor with a constant velocity of 12 m/s. How far will it have
gone after 6 seconds?

Answers

Answer:

72m

12m x 6s=72m

there ya go

You would do 12x6 to get the velocity. After 6 seconds it would be 72m/s

A planet with a mass one-half that of Earth has a radius that is 3 times that of Earth's radius. What is the gravitational field strength of the planet?

Answers

The gravitational acceleration of a planet is proportional to the planet's mass, and inversely proportional to square of the planet's radius.

So when you stand on the surface of this particular planet, you feel a force of gravity that is

(1/2) / (3²)

of the force that you feel on the surface of the Earth.

That's (1/18) as much as on Earth.

The acceleration of gravity there would be about 0.545 m/s².  

This is about 12% less than the gravity on Pluto.

A reaction occurs when a compound breaks down. This reaction has one reactant and two or more products. Energy, as from a battery, is usually needed to break the compound apart.

Answers

Answer:

decomposition

Explanation:

A stream moving with a speed of 0.5 m/s reaches a point
where the cross-sectional area of the stream decreases to
one-fourth of the original area. What is the water speed in
this narrowed portion of the stream?

Answers

Explanation:

hi I like help but I couldn't

A 3.0-kilogram object initially at rest explodes and splits into three fragments. One fragment has a mass of 0.50 kg and flies off along the negative x axis at a speed of 2.8 m/s, and another has a mass of 1.3 kg and flies off along the negative y axis at a speed of 1.5 m/s.

Required:
What are the speed and direction of the third fragment?

Answers

Answer:

The speed and direction of the third fragment are 2 meters per second and 54.316º, respectively.

Explanation:

The object is not under the influence of any external force, meaning that Principle of Momentum Conservation to calculation of the velocity of the third fragment:

[tex](m_{1}+m_{2}+m_{3})\cdot \vec {v}_{o} = m_{1}\cdot \vec v_{1} + m_{2}\cdot \vec v_{2} + m_{3}\cdot \vec v_{3}[/tex] (1)

Where:

[tex]m_{1}[/tex], [tex]m_{2}[/tex], [tex]m_{3}[/tex] - Masses of the first, second and third fragments, in kilograms.

[tex]\vec v_{o}[/tex] - Initial velocity of the object, in meters per second.

[tex]\vec v_{1}[/tex], [tex]\vec v_{2}[/tex], [tex]\vec v_{3}[/tex] - Velocities of the first, second and third fragments, in meters per second.

If we know that [tex]m_{1} = 0.5\,kg[/tex], [tex]m_{2} = 1.3\,kg[/tex], [tex]m_{3} = 1.2\,kg[/tex], [tex]\vec v_{o} = (0,0)\,\left[\frac{m}{s} \right][/tex], [tex]\vec v_{1} = \left(-2.8, 0\right)\,\left[\frac{m}{s} \right][/tex] and [tex]\vec v_{2} = \left(0,-1.5\right)\,\left[\frac{m}{s} \right][/tex], the velocity of the third fragment is:

[tex](-1.4,0) + (0,-1.95) + 1.2\cdot \vec v_{3} = (0,0)[/tex]

[tex]1.2\cdot \vec v_{3} = (1.4,1.95)[/tex]

[tex]\vec v_{3} = (1.167, 1.625)\,\left[\frac{m}{s} \right][/tex]

The speed of the third fragment is the magnitude of the result found above:

[tex]v_{3} = 2\,\frac{m}{s}[/tex]

And the direction of the third fragment is:

[tex]\theta_{3} = \tan^{-1} \left(\frac{1.625}{1.167}\right)[/tex]

[tex]\theta_{3} \approx 54.316^{\circ}[/tex]

The speed and direction of the third fragment are 2 meters per second and 54.316º, respectively.

g 1. To see why an MRI utilizes iron to increase the magnetic field created by a coil, calculate the current needed in a 400-loop-per-meter circular coil 0.660 m in radius to create a 1.20-T field (typical of an MRI instrument) at its center with no iron present. The magnetic field of a proton is approximately like that of a circular current loop in radius carrying . What is the field at the

Answers

Answer:

I = 2387.32 A

Explanation:

Given that,

Number of turns in the loop, N = 400

The radius of the circular coil, r = 0.66 m

The magnetic field inside the MRI, B = 1.2 T

We need to find the current in the loop. The magnetic field inside the solenoid is given by :

[tex]B=\mu_o NI\\\\I=\dfrac{B}{\mu_o N}\\\\I=\dfrac{1.2}{4\pi \times 10^{-7}\times 400}\\\\I=2387.32\ A[/tex]

So, the required current is equal to 2387.32 A.

A snail traveled 3.12 meters in 27.13 minutes. What is the snails speed in meters per second

Answers

Answer:

0.002 m/s

Explanation:

27.13(60) = 1,627.8 seconds

3.12/1,627.8 = 0.00191 ≈ 0.002 = s

Are you sure you're not looking for cm/s?

what is the distance a train can travel if its speed is 20mph over a time of 5.6 hours (show all 3 steps)

Answers

Answer:

distance = 112 miles

Explanation:

its 12 miles every 0.6 in a hour

The gravitational force between two objects with masses 1kg and 28kg separated by a distance 7m is ____________10-11 N.


a.
3.81

b.
26.68

c.
9151.24

d.
1307.32
Hhhhhellllppp fastt​

Answers

Answer:

a. 3.81

Explanation:

F = GMm/r^2

F = (6.67 x 10^-11 x 28 x 1) / 7^2

F = 3.81 x 10^-11 N

Investigator Daniels is working on the scene of a suspected arson on a rainy evening. The site of the fire was a mechanic's garage, so there are plenty of accelerants
on the scene. According to the owner of the garage, there had been an argument with a customer the day before about his motorcycle. All the employees left by
6:00 pm. The office was unharmed but there is much damage in the mechanic's bay area and toolboxes. The flames look to have been most concentrated around a
bucket that the owner says was filled with oily rags. She is trying to sift through the evidence and find the relevant facts of the case so far. In order to effectively
Identify the relevant facts, Investigator Daniels creates a word bank. Which word would not fit into her word bank?
Argument
Rainy
Olly rags
Toolboxes

Answers

Answer:

Rainy

Explanation:

It is the only one that has nothing to do with the case

someone please help I can mark brainless

Answers

The answer here is B I hope that helps you if not I’m really sorry

A falling 0.60 kg object experiences a frictional force due to air resistance of 1.5 N. What is the object's acceleration?​

Answers

Answer:

7.5 m/s².

Explanation:

From the question given above, the following data were:

Mass (m) of object = 0.6 Kg

Force of friction (Fբ) = 1.5 N

Acceleration (a) =?

Next, we shall determine the force of gravity on the object. This can be obtained as follow:

Mass (m) of object = 0.6 Kg

Acceleration due to gravity (g) = 10 m/s²

Force of gravity (F₉) =?

F₉ = mg

F₉ = 0.6 × 10

F₉ = 6 N

Next, we shall determine the net force acting on the object. This can be obtained as follow:

Force of friction (Fբ) = 1.5 N

Force of gravity (F₉) = 6 N

Net force (Fₙ) =?

Fₙ = F₉ – Fբ

Fₙ = 6 – 1.5

Fₙ = 4.5 N

Finally, we shall determine the acceleration of the object. This can be obtained as follow:

Mass (m) of object = 0.6 Kg

Net force (Fₙ) = 4.5 N

Acceleration (a) of object =?

Fₙ = ma

4.5 = 0.6 × a

Divide both side by 0.6

a = 4.5 / 0.6

a = 7.5 m/s²

Therefore, the acceleration of the object is 7.5 m/s²

PLEASE HELP WILL GIVE BRALIEST

12. A bird flies 10 m in 2 seconds. What is its speed?


13. A plane takes 8 hours to fly 5000 km. What is its speed?


14. When given a motion graph, how can you tell if it’s a speed graph or acceleration graph?

Answers

Answer:

12: If the bird flies 10m in 2s, it's speed is then 10m/2s, which we can simplify giving us 5m/s

13: Flying 5000 km in eight hours means that it's flying at (5000 / 8)km/h, or 625km/h

14: A speed graph will not go below zero, an acceleration graph will.


A runner having mass of 55 kg moving at a speed of 9 m/s rounds a bend with a radius of 18 m. What is the centripetal

Answers

Answer:

247.5 N

Explanation:

From the question,

The expression of centriputal force is given as

F = mv²/r..................... Equation 1

Where m = mass of the runner, v = velocity of the runner, r = radius of the runner

Given: m = 55 kg, v = 9 m/s, r = 18 m

Substitute these values into equation 1

F = 55(9²)/18

F = 247.5 N.

Hence the centriputal force of the runner is

247.5 N


A car's initial speed of 15m/s is running with the acceleration of 32m/
s2 in 8 seconds. What is the car's final velocity?

Answers

Explanation:

15m/s

acceleration= (+)

so, 15m/s +32m/s=47m/s

42m/s. X 8 = 336

What are some possible factors that can be the X
and Y axis of a motion graph?

Answers

Answer:

x-Speed/velocity

y-time.

Explanation:

because Speed is a rate of change of distance while time how long it takes a a car to move to a specific point

A train with proper length L has clocks at the front and back. A photon is fired from the front to the back. Working in the train frame, we can easily say that if the photon leaves the front of the train when a clock there reads zero, then it arrives at the back when a clock there reads L/c. Now consider this setup in the ground frame, where the train travels by at speed v. Rederive the above frame-independent result (namely, if the photon leaves the front of the train when a clock there reads zero, then it arrives at the back when a clock there reads L/c) by working only in the ground frame.

Answers

Explanation:

In train's rest frame, the speed of photon is [tex]c[/tex] and the proper length of the train is [tex]L[/tex]. The time taken by the photon to cross the train is [tex]t=\frac{L}{c}[/tex]

In ground frame, the speed of the photon is given as follows:

[tex]v_{x}=\frac{v_{x}+v}{1+\frac{v_{x} \cdot v}{c^{2}}}[/tex]

[tex]=\frac{c+v}{1+\frac{c v}{c^{2}}} \\=c[/tex]

The speed of light or photon remains same in every frame of reference.

Now, the speed of train is very less as compared to the speed of photon so that [tex]v<c[/tex] So that, [tex]\frac{v}{c} \ll 1[/tex]

The length contraction in the ground frame is given as follows:

[tex]L^{\prime}=L \sqrt{1-\frac{v^{2}}{c^{2}}}[/tex]

[tex]=L[/tex]

Time taken by the photon to travel the length of the train in ground frame is .

. Assume that the batter does hit the ball. If the bat's instantaneous angular velocity is 30 rad/s at the instant of contact, and the distance from the sweet spot on the bat to the axis of rotation is 1.25 m, what is the instantaneous linear velocity of the sweet spot at the instant of ball contact

Answers

Answer:

37.5 m/s

Explanation:

Using,

Formula

v = ωr....................... Equation 1

Where ω = instantaneous angular velocity, v = instantaneous linear velocity, r = radius or distance from the sweet spot of the bat to the axis of rotation.

From the question,

Given: ω = 30 rad/s, r = 1.25 m

Substitute these values into equation 1

v = 30(1.25)

v = 37.5 m/s.

Hence the instantaneous linear velocity of the sweet spot at the instant of ball contact is 37.5 m/s

A bump should primarily be used in which situation?

A. when the ball is going out of bounds
B. when returning a serve
C. to start game play

Answers

The answer is b to the question

Match each type of wave made during an earthquake to its wave form.

Answers

Answer:

I see anything so I can answer you .

write the definition
Heredity, Dominant allele, recessive allele, probability, genotype, phenotype

Answers

Explanation:

Heredity: The passing on of physical or mental characteristics genetically from one generation to another.

Dominant allele: In genetics, dominance is the phenomenon of one variant of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and the second recessive.

Answer:

Heredity: the passing on of physical or mental characteristics genetically from one generation to another.

Dominant Allele: a variation of a gene that will produce a certain phenotype, even in the presence of other alleles.

Recessive Allele: a variety of genetic code that does not create a phenotype if a dominant allele is present.

Probablity: used to measure the chance or likelihood of an event to occur.

Genotype: an organism's complete set of genetic material

Phenotype: the set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Q1what is pinhole camera?​

Answers

A pinhole camera is a simple camera without a lens but with a tiny aperture (the so-called pinhole)—effectively a light-proof box with a small hole in one side. Light from a scene passes through the aperture and projects an inverted image on the opposite side of the box, which is known as the camera obscura effect.

A girl weighing 45kg is standing on the floor, exerting a downward force of 200N on the floor. The force exerted on her by the floor is ..............

Select one:

a.
No force exerted


b.
Less than 2000N


c.
Equal to 200 N


d.
Greater than 200 N​

Answers

Answer:

c.

Equal to 200 N..........

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Jolie uses the following equation to determine how much a taxi ride is going to cost her, where m is the number of miles traveledduring the trip$6.00 + $2.60m = $29.40Using the equation, how many miles did she ride?A.11B. 8C. 9D. 7 find the value of x. que fueron las cortes de cadiz en el siglo XIXes urgenteeee Write down in terms of n, an expression for the nth termof the following sequences:a) 2 5 8 11 14b) 9 11 13 15 17 PLEASE HELP VERY IMPORTANT Compara cele doua ipostaze ale la unui care asigura simetria textului referindu-Te la reacia acestuia fa de tririle ndrgostitului Which word best completes the sentence?Select the word from the drop-down menu.To save the company, we will Choose... 1 abslove 2 redo 3 subordinte 4 transend our long-term goals and focus on our immediate priorities. Fill in the blanks to complete a summary of the entire passage. i need help //////// how did plants move from water to land how did that change life on earth? Which of the following was brought into the mail kingdom during the time of mansa musa A. Timbuktu B. MogadishuC. Mombasa D. Kilwa How did the African Empires interact with other empires of their time? Circumference of a circle is 14 pi what is the area in square inches express your answer in terms of pie I need help please, I will give brainliest to the first person that answers "the difference of p and 4." A student is developing a program that allows users to look up the definitions of words that appear in a book.The student plans to perform a large number of searches through a dictionary containing words and their definitions. The student will use a procedure written by a computer scientist to quickly search the dictionary (and knows that the procedure will return a definition if one is available). The student cannot modify the search procedure written by the computer scientist but can call the procedure by supplying a word.Which of the following is a true statement about the students use of the computer.The student is changing the search procedures internal abstractions.The student is modifying the search procedure to take a definition as an argument and return the corresponding word.The student is reusing the computer scientists procedural abstraction by knowing what the procedure does without knowing how it does it.The student is reusing the computer scientists procedural abstraction by using duplicate code each time a search needs to occur. Which organ detects stimuli from the environment and is part of the nervous system?Group of answer choicesA. eyeB. stomachC. heartD. lungs Define Equivalent RatesPlease answer this asap- Which of these best describes fossils?A. nonexistentB. easily formedC. important and rareD. common and unhelpful during the age of Napoleon stage of the French Revolution what actions were taken to address issues in france ? to what extent did those actions fix those problems?