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jenyasd209 [6]
3 years ago
5

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

hat is its new resistance
Physics
1 answer:
never [62]3 years ago
3 0

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

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A particle with kinetic energy equal to 282 J has a momentum of magnitude 26.4 kg · m/s. Calculate the speed (in m/s) and the ma
masha68 [24]

Answer:

v=21.36\,\,\frac{m}{s}\\

m=1.2357\,\,kg

Explanation:

Recall the formula for linear momentum (p):

p = m\,v  which in our case equals 26.4 kg m/s

and notice that the kinetic energy can be written in terms of the linear momentum (p) as shown below:

K=\frac{1}{2} m\,v^2=\frac{1}{2} \frac{m^2\,v^2}{m} =\frac{1}{2}\frac{(m\,v)^2}{m} =\frac{p^2}{2\,m}

Then, we can solve for the mass (m) given the information we have on the kinetic energy and momentum of the particle:

K=\frac{p^2}{2\,m}\\282=\frac{26.4^2}{2\,m}\\m=\frac{26.4^2}{2\,(282)}\,kg\\m=1.2357\,\,kg

Now by knowing the particle's mass, we use the momentum formula to find its speed:

p=m\,v\\26.4=1.2357\,v\\v=\frac{26.4}{1.2357} \,\frac{m}{s} \\v=21.36\,\,\frac{m}{s}

4 0
3 years ago
A tightrope walker wants to know the tension used to support the rope that is suspended between two poles. The rope is 18 m long
Alla [95]

Answer:

T = 29.6 N

Explanation:

length of the rope is

L = 18 m

mass of the rope is

m = 12 kg

now we have

mass per unit length of the rope is given as

[te]\lambda = \frac{12 kg}{18 m}[/tex]

now time taken by wave to reach from end to other

t = \frac{L}{v}

2.7 s = \frac{18}{v}

v = 6.67 m/s

now we have

v = \sqrt{\frac{T}{\lambda}}

6.67 = \sqrt{\frac{T}{0.67}}

so we will have

T = 29.6 N

5 0
4 years ago
How much current would flow in a device powered by four 1.5 V batteries through a bulb that had a resistance of 51.0 ohms?
Serhud [2]

Answer:

0.12A

Explanation:

Total voltage produced by the batteries;

V = 1.5 × 4 = 6 v

Then the current that is flowing through the device

Current(I) = V/R

; I = 6/51

;Current = 0.12A

4 0
3 years ago
Fl-19 in florida, if your pwc is equipped with an engine cut-off lanyard, what must you do with it?
melamori03 [73]

Answer: Attach it to clothing, personal flotation device or the person's person.

Explanation:

This particular Question or problem has to do with the rules and regulations or laws governing the use of Personal Watercraft(PWC) in the state of Florida in the United States of America. Hence, one of the rules that is applicable to the use of boats and waterways or the use of personal watercraft in Florida is that in florida, if ones pwc is equipped with an engine cut-off lanyard the person operating it must ATTACH IT TO THE CLOTHING, PERSONAL FLOATATION DEVICE IR THE OPERATORS' PERSON.

Another rule band the use of flammable personal flotation device with Personal Watercraft(PWC) in the state of Florida. All this rules and guildlines are made to limit or minimize hazards.

3 0
3 years ago
The mass of an atom is ________________________.
andreyandreev [35.5K]
I'd say d.) Concentrated in the nucleus.

This is because Nucleus consists of protons and neutrons; contributing to some mass, whereas Electron's mass is almost negligible ( 9.1 x 10^-31 kg) 

Hope this answers your question!
8 0
3 years ago
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