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
Orlov [11]
3 years ago
13

A 2.1-mF capacitor is discharged through a 4.0-kΩ resistor. How long will it take for the capacitor to lose half its initial sto

red energy?
(A) 5.82 s
(B) 2.91 s
(C) 0.660 s
(D) 4.20 s
(E) 8.40 s
Physics
1 answer:
Harrizon [31]3 years ago
4 0

Answer:

the answer is a)5.82s

Explanation:

Hello!

The first thing we must understand to solve this exercise is that a capacitor has the following characteristic function

V=(Vo)e^{-t/RC}

where

Vo=initial voltage

V=voltage in an instant of time

t=time

R=resistance=4000Ω

C=capacitance=2.1-mF=0.0021F

we must consider that the final voltage is half of the initial voltage so we deduce the following equation

V=Vo/2

Now we replace in the initial equation, and start an algebraic process to find t

\frac{Vo}{2} =(Vo)e^{-t/RC}\\0.5=e^{-t/RC}\\ln(0.5)=ln(e^{-t/RC})\\ln(0.5)=\frac{-t}{RC} \\t=-(RC)ln0.5

finally with the equation ready, we use the resistance and capacitance values ​​to find the time value

t=-(4000)(0.0021)ln(0.5)=5.82s

the answer is a)5.82s

You might be interested in
A total charge of 9.0 mC passes through a cross-sectional area of a nichrome wire in 3.6s. The number of electrons passing throu
Setler79 [48]
<h2>Given :</h2>

  • total charge = 9.0 mC = 0.009 C

Each electron has a charge of :

1.6 \times 10 {}^{ - 19} \:  C

For producing 1 Cuolomb charge we need :

  • \mathrm{\dfrac{1}{1.6 \times 10 {}^{ - 19} } }

  • \dfrac{10 {}^{19} }{1.6}

  • \dfrac{10\times 10 {}^{19} }{16}

  • \dfrac{100 \times 10 {}^{18} }{16}

  • \mathrm{6.24 \times 10 {}^{18}  \:  \: electrons}

Now, for producing 0.009 C of charge, the number of electrons required is :

  • 0.009 \times 6.24 \times  {10}^{18}

  • 0.05616 \times 10 {}^{18}

  • \mathrm{5.616 \times 10 {}^{16}  \:  \: electons}

_____________________________

So, Number of electrons passing through the cross section in 3.6 seconds is :

\mathrm{5.616 \times 10 {}^{16} \:  \: electrons}

Number of electrons passing through it in 1 Second is :

  • \dfrac{5.616 \times  {10}^{16} }{3.6}

  • \mathrm{1.56 \times 10 {}^{16}  \:  \: electrons}

Now, in 10 seconds the number of electrons passing through it is :

  • 10 \times  \mathrm{1.56 \times 10 {}^{16}  \:  \: }

  • \mathrm{1.56 \times 10 {}^{17}  \:  \: electrons}

_____________________________

\mathrm{ \#TeeNForeveR}

6 0
3 years ago
A solid conducting sphere with radius R that carries positive charge Q is concentric with a very thin insulating shell of radius
chubhunter [2.5K]

Answer:

a) 0 < r < R: E = 0, R < r < 2R: E = KQ/r^2, r > 2R: E = 2KQ/r^2

b) See the picture

Explanation:

We can use Gauss's law to find the electric field in all the regions:

EA = qen/e0 where qen is the enclosed charge

Remember that the electric field everywhere outside a sphere is:

E(r) = q/(4*pi*eo*r^2) = Kq/r^2

a)

  1. For 0 < r < R: There is not enclosed charge because all of it remains on the outer layer of the conducting sphere, therefore E = 0                       EA = 0/e0 = 0                                                                                                    E = 0
  2. For R < r < 2R: Here the enclosed charge is equal Q                                      E =  Q/(4*pi*eo*r^2) = KQ/r^2      
  3. For r > 2R: Here the enclosed charge is equal 2Q                                              E =  Q/(4*pi*eo*r^2) + Q/(4*pi*eo*r^2) = 2Q/(4*pi*eo*r^2) = 2KQ/r^2

b)  At the beginning there is no electric field this is why you see a line in zero, In R the electric field is maximum and then it starts to decrease exponentially with the distance and finally in 2R the field increase a little due to the second sphere to then continue decreasing exponentially with the distance

7 0
3 years ago
A manufacturer had 5 business locations. The producer always dealt with the manufacture's office manager for policy changes. The
Arturiano [62]
Tuberculosis. Reason: I just took the test and got it right
3 0
3 years ago
And metamorphic rock is classified according to its
ICE Princess25 [194]
The answer is basis of texture
8 0
3 years ago
Read 2 more answers
You can hide a row or a column by using the Hide command or by setting the row height or column width to ____________.
Marianna [84]

Answer:

0

Explanation:

Suppose this is for Excel. You can hide a row or a column by right-clicking on that row/column header and select row height or column width. After that simply input in 0 and click OK. The row or column will be hidden in the end, just like using a Hide command.

3 0
3 years ago
Other questions:
  • Why are there no hurricanes in Alaska?
    12·2 answers
  • 1.How can you conserve water in the kitchen?
    15·1 answer
  • Main ingredient of all cells
    11·1 answer
  • Is it plagiarism/copying to do a science fair project that is similar to one that has been done already, if you modify certain a
    12·2 answers
  • (1- name 1 of Faouzia’s songs from her stripped album
    12·1 answer
  • Which occurs when two musical instruments use resonance?
    13·2 answers
  • (c) Due to up thrust
    5·1 answer
  • Two identical air-filled parallel-plate capacitors C1 and C2 are connected in series to a battery that has voltage V. The charge
    13·1 answer
  • What force is needed to accelerate a 2000kg car to 15m/S2
    12·1 answer
  • If you drop an object, it will accelerate downward at a rate of 9.8 meters per second per second. if you instead throw it downwa
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!