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
nirvana33 [79]
3 years ago
13

A 20.0 μF capacitor initially charged to 30.0 μC is discharged through a 1.20 kΩ resistor. How long does it take to reduce the c

apacitor's charge to 15.0 μC
Physics
1 answer:
Kay [80]3 years ago
3 0

Answer:

16.6 ms or 0.0166 s

Explanation:

If Q is the final charge, Q' is the initial charge, C the capacitance ,R is the resistance , t the time taken  and τ the time constant,

[tex]Q = Q'( 1- e^{-t\div \tau })

τ = R C = (1.20×10³) (20×10⁻⁶) = 0.024 s

15 = 30 ( 1- e^{-t\div \ 0.024 })

( 1- e^{-t\div \ 0.024 }) = 15 ÷ 30

⇒ - e^{-t\div \ 0.024 }) = 0.5 -1  

⇒  e^{-t\div \ 0.024 }) = 0.5

Taking logarithm to the base e on both sides of this equation,

⇒ t = 0.0166 seconds = 16.6 milli seconds

You might be interested in
Answer the answers that you know.
sesenic [268]
1).  Sequence from the Sun:

       Inner planets:
                 Mercury
                 Venus
                 Earth
                 Mars

       Outer planets:
                 Jupiter
                 Saturn
                 Uranus
                 Neptune
            
2).  The farther a planet is from the sun, the longer it takes
to orbit the sun.  Mercury ... 88 days.  Earth ... 365 days.
                           Jupiter ... 12 years.    Neptune ... 165 years.

3).  Mercury & Venus ... no moons
      Earth - 1
      Mars - 2
     Jupiter -  more than 65

4).  Mercury ... cratered, no atmosphere
      Venus ... cratered, thick cloudy atmosphere
       Mars ... dry, cratered, slight atmosphere, like 1% or Earth's
      
       Jupiter, Saturn, Uranus, Neptune
                     We can't see any surface.  If any of them even
                     HAS a surface, it's thousands of miles under a
                     thick atmosphere of methane gas.

5).  Missing from the list

6).  Here's a list from the biggest planet to the smallest one.
The numbers in parentheses are the radius of the planet --
half of the diameter:

Jupiter (69,911 km / 43,441 miles) – 1,120% the size of Earth
Saturn (58,232 km / 36,184 miles) – 945% the size of Earth
Uranus (25,362 km / 15,759 miles) – 400% the size of Earth
Neptune (24,622 km / 15,299 miles) – 388% the size of Earth
Earth (6,371 km / 3,959 miles)
Venus (6,052 km / 3,761 miles) – 95% the size of Earth
Mars (3,390 km / 2,460 miles) – 53% the size of Earth
Mercury (2,440 km / 1,516 miles) – 38% the size of Earth

7). At least seven of the planets rotate in the same direction. 
There's something different about one of them ... it may be Uranus
but I'm not sure.  You'll have to look this up.

8).  Saturn has the famous rings, that you can almost see
with only binoculars.
Spacecraft sent to observe the outer planets have detected
very thin rings around Uranus and Neptune.

9).  Included in #6.

10).  I don't have complete info.  Generally, the closer the planet
is to the sun, the hotter it is.  But there are a few exceptions. 
I think Venus ... the second one from the sun, is actually hotter
than Mercury. 

11).  Just about every language has its own name for each planet.

12).  "Terrestrial" means "like Earth" ("Terra").
The terrestrial planets are the ones that have solid surfaces
and are made of rock.
Mercury, Venus, Earth, and Mars.

13).  "Jovian" means "like Jupiter".
Either no solid surface, or very small, inside a big deep gas ball. 
Jupiter, Saturn, Uranus, Neptune.


4 0
3 years ago
A proposed communication satellite would revolve around the earth in a circular orbit in the equatorial plane at a height of 358
aleksandr82 [10.1K]

Answer:

Period is 86811.5 seconds.

Explanation:

{ \boxed{ \bf{T {}^{2} =  (\frac{4 {\pi}^{2} }{GM}) {r}^{3}   }}}

{ \tt{T {}^{2}  =  \frac{4 {(3.14)}^{2} }{(6.6 \times  {10}^{ - 11} ) \times (5.98 \times  {10}^{24} )} \times  {((35880\times  {10}^{3}) } + (6370 \times  {10}^{3} )) {}^{3}   }} \\  \\ { \tt{T {}^{2}  =  7.54 \times {10}^{9} }} \\ { \tt{T =  \sqrt{7.54 \times  {10}^{9} } }} \\ { \tt{T = 86811.5 \: seconds}}

6 0
3 years ago
PLEASE HELP ASAP!!
Stells [14]

Its B: reduce the amount of energy needed to do the work by putting the work onto something else

3 0
3 years ago
Read 2 more answers
<img src="https://tex.z-dn.net/?f=%20%5Chuge%5Ctextbf%7BHelp%7D%20" id="TexFormula1" title=" \huge\textbf{Help} " alt=" \huge\te
Aleks [24]

Answer:

Geometrical optics, or ray optics, describes the propagation of light in terms of "rays" which travel in straight lines, and whose paths are governed by the laws of reflection and refraction at interfaces between different media.

5 0
2 years ago
Read 2 more answers
When does radioactive decay occur
castortr0y [4]

Answer:

C.when the nucleus decays

Explanation:

In chemical reactions, the outermost electrons of atoms are re-arranged somehow without the involvement of the nuclei of the participating atoms of the elements.

Nuclear reactions causes changes within the atomic nucleus. For every atomic nucleus, a specific neutron/proton ratio ensures stability. When the stability ratio differs an atom becomes unstable and splits into one or more other nuclei with the emission of small particles of matter. This is what radioactivity entails.

8 0
3 years ago
Other questions:
  • Water particles in an ocean wave move in circles. This particle movement causes a wooden raft to...
    9·2 answers
  • You are in a helicopter towing a 125-kg laser detector that mapping out the thickness of the Brunt Ice Shelf along the coast of
    5·1 answer
  • How far will a football travel if it is booted at a speed of 15 m/s and travels for 3 seconds?
    12·1 answer
  • The lengths of two sides of a right triangle are given.Find the length of the third side. Round to the nearest tenth if necessar
    10·1 answer
  • To get an electrical current you have to have a ___ ____.
    13·2 answers
  • A person standing at the edge of a seaside cliff kicks a stone horizontally over the edge with a speed of 18 m/s. The cliff is 5
    11·1 answer
  • Some curious students hold a rolling race by rolling four items down a steep hill. The four items are a solid homogeneous sphere
    11·1 answer
  • A bullet is shot horizontally from shoulder height (1.5 m) with an initial speed 200 m/s. (a) How much time elapses before the b
    12·1 answer
  • Calculate the speed of an object which Travels 30 km distance in 4 hours​
    13·1 answer
  • An engineer has the task of producing an aluminum alloy with a density of 3.0 grams per cubic centimeter. She comes up with the
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!