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
rewona [7]
3 years ago
9

Two point charges of -7uC and 4uC are a distance of 20

Physics
2 answers:
aivan3 [116]3 years ago
8 0

Answer:

Approximately 0.979 J.

Explanation:

Assume that the two charges are in vacuum. Apply the coulomb's law to find their initial and final electrical potential energy \mathrm{EPE}.

\displaystyle \mathrm{EPE} = \frac{k \cdot q_1 \cdot q_2}{r},

where

  • The coulomb's constant k = 8.99\times 10^{9}\; \rm N\cdot m^{2} \cdot C^{-2},
  • q_1 and q_2 are the sizes of the two charges, and
  • r is the separation of (the center of) the two charges.

Note that there's no negative sign before the fraction.

Make sure that all values are in SI units:

  • q_1 = -7\rm \;\mu C = -7\times 10^{-6}\; C;
  • q_2 = 4\rm \;\mu C = 4\times 10^{-6}\; C;
  • Initial separation: \rm 20\; cm = 0.20\; cm;
  • Final separation: \rm 90\; cm = 0.90\; cm.

Apply Coulomb's law:

Initial potential energy:

\begin{aligned} \frac{k \cdot q_1 \cdot q_2}{r} &= \frac{8.99\times 10^{9}\times (-7\times 10^{-6})\times 4\times 10^{-6}}{0.20}\\&= \rm -1.2586\; J\end{aligned}.

Final potential energy:

\begin{aligned} \frac{k \cdot q_1 \cdot q_2}{r} &= \frac{8.99\times 10^{9}\times (-7\times 10^{-6})\times 4\times 10^{-6}}{0.90}\\&= \rm -0.279689\; J\end{aligned}.

The final potential energy is less negative than the initial one. In other words, the two particles gain energy in this process. The energy difference (final minus initial) will be equal to the work required to move them at a constant speed.

\begin{aligned}\text{Work required} &= \text{Final EPE} - \text{Initial EPE}\\&= \rm  -0.279689\; J - (-1.2586\; J)\\&\approx 0.979\; J\end{aligned}.

olga2289 [7]3 years ago
3 0

Answer:

Answer is c

Explanation:

trust me.

You might be interested in
Calculate the average velocity of a motor cycle that travels 72km/hr in<br> 20 seconds
olchik [2.2K]
Velocity =displacement
Change in time
D=72km/hr
Time=20s
But the S.I unit of velocity is m/s so you woul have to change 72km/hr to m/s

Changing 72km to m

1 kilometer=1000meters
Then, 72 kilometers =?

72•1000/1
=72000m

Changing 72hours to seconds

If 1 hour = 3600 seconds
Then 72 hours=?

72•3600/1

=259200 seconds


Velocity =displacement
Change in time

V= 72,000
259,2005
=0.028m/s
3 0
3 years ago
You are camping in the breathtaking mountains if Colorado. You spy an unopened diet soda can floating motionless below the surfa
Pavel [41]

Answer:

C. Up, equal to the can's weight

Explanation:

You are camping in the breathtaking mountains if Colorado. You spy an unopened diet soda can floating motionless below the surface of a lake. What is the direction and amount of force the water exerts on it?

A. Zero

B. Down, equal to the can's weight

C. Up, equal to the can's weight

D. Not enough information is given

from the principle of flotation which states that a

When a body displaces a weight of water equal to its own weight, it floats. : A floating object displaces a weight of fluid equal to its own weight. ... Archimedes' principle equates the buoyant force to the weight of the fluid displaced.

the upthrust (this is the upward vertical force exerted on an object in fluid)in the water equals the weight of the body in water it floats.

7 0
2 years ago
What is less dense water or oil steel or water helium or air or oil or water
Leni [432]

Answer:

air because their is nothing contained within the air other than all the solutions that you have listed

Explanation:

4 0
3 years ago
Read 2 more answers
Which statement is true?
Fynjy0 [20]
If it's Kepler's law of equal areas you're talking about,
then the first of the four statements is true.
4 0
3 years ago
Read 2 more answers
If you and 3 friends are playing tug of war and are pulling with a force of 35 N and your teammate with 37 N, while your opponen
mash [69]
72N and 75N. no. hope it helps you
3 0
3 years ago
Other questions:
  • A person jumps from the roof of a house 3.1-m high. When he strikes the ground below, he bends his knees so that his torso decel
    15·1 answer
  • In addition to births and deaths what else can influence the population growth rate ?
    10·1 answer
  • A women who normally weighs 400 N stands on top of a ladder so high she is one full additional earth radius above the surface of
    7·1 answer
  • Suppose the demand for air travel decreases (as illustrated in the graph below). A decrease in demand _____ the equilibrium pric
    15·1 answer
  • A car moving at a velocity of 25m/s, so how much distance it will travel in 5 seconds?
    8·1 answer
  • Only two electrons, with opposing spins, are allowed in each orbital is known as the
    5·1 answer
  • A thug pushes some 100 kg punk with 300 N of force. How much is the punk accelerated?
    6·1 answer
  • Goals can be big or small? Question 1 options: True False
    12·1 answer
  • WhT is marasmus my followers and following pls give answer in detail ​
    12·2 answers
  • Do you think some can freezing when it hot? why or why not
    11·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!