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# Charge

An electric charge is the physical property of matter that causes it to experience a force when closed to other electrically charged matter. There are two types of electric charges, positive and negative. Positively charged substances are repelled from other positively charged substances, but are attracted to negatively charged substances. Similarly, negatively charged substances are repelled from negative and attracted to positive. A substance will be negatively charged if it has an excess of electrons and will otherwise by positively charged or uncharged. The SI unit for electric charge is a coulomb (C).

The electric charge is a fundamental conserved property of some subatomic particle, which determines their electromagnetic interaction. Electrically charged matter is influenced by and will produce electromagnetic fields. This interaction between a moving charge and an electromagnetic field is the source of the electromagnetic force. The electromagnetic force is one of the four fundamental forces.

The charge of an electron is -1 and the charge of a proton is +1. Coulomb’s law quantifies the electrostatic force between two particles by asserting that the force is proportional to the product of their charges and inversely proportional to the square of the distance between them.

The charge of an antiparticle is equal to the corresponding particle but with an opposite sign. Quarks have fractional charges of either -1/3 or +2/3. Free standing quarks have never been observed.

An ion is an atom which has lost at least one electron. This would give it a net positive charge (cation) or has grained at least one electron, giving it a net negative charge (anion). Monatomic ions are formed from single atoms. Polyatomic ions are formed from two or more atoms that have bonded together. Each case yields an ion with a positive or negative net charge.

## BrainMass Categories within Charge

### Physics: Electric Fields and Positive Charges

See the attached file. 1. In a radical system the electric potential is given by the function V(r)=k(1/r2 - 1/r) Where k is constant and r is the radical distance. a. Find the electric field as a function of distance. b. If a positive charge was released in this system, at what radius would it be at equilibrium (i.e

### Octahedral Distortion to D2d and D2h

The octahedra of anatase and rutile TiO2 both have elongation along the z-axis (apical). Anatase experiences more angular distortion around the equatorial bonds. Why is anatase classified as D2d (meaning the dz^2, dxz and dyz states have an INCREASE in energy), while rutile is D2h (meaning these states have LOWER energy), if bot

### Processes of a Neuron

I need help in explaining the process a neuron undergoes when going from a resting potential to an action potential to the release of its neurotransmitters. I am not too sure how to approach this because I do not really understand the process myself.

### Maxwell's Equations, Component-Wise

Write out Maxwell's Equations component-wise in cylindrical coordinates in their most general form. Remember that each field component can be a function of all three spatial dimensions as well as time. You should end up with eight equations. Assume that all source terms are present, or that there exists both a charge density a

### Electrostatic Field and Potential in Spheres

See the attached file. 1. The electrostatic field E in a particular region can be expressed in terms of spherical coordinates. Derive an expression for the potential difference. 2. The electrostatic potential in a region is given by a function. Derive an expression for the electrostatic field in this region, and hence dete

### Motion of charged particle in uniform electric & magnetic fields

In this question we will consider the motion of a charged particle in uniform electric and magnetic fields that are perpendicular. You may ignore the effects of gravity throughout this question. (a)(i) Consider a charged particle of mass m and charge q that is moving in a uniform electric field E = Ee_y and a perpendicular u

### Physics: Car Accident Collision Question.

My dad got charged for a hit and run. He was driving a Ford Edge that weighs 5,380lbs and struck an 8 year old boy that stepped out infront of his car. The kid weighs 57lbs and my dad was going at a speed of 25mph. He had the radio turned up pretty loud. Would he feel any impact? The kid was not run over by the tire.

### Problems in Electromagnetism

A straight wire along the z axis carries a charge density lamda traveling in the +z direction at speed v. Construct the field tensor at the point (x,0,0) Explain why the electric field has to be (2*lamda)/(4*pi*epsilon*x) Explain what will happen if the problem changes to (y,0,0) for example.

Exercise11-18: A whistle-blower in her allegations made in a qui tam suit, alleged that her former employer fired her because she told the company that it was "padding the bills" to the federal government for the cost-plus contract it had to build ejection seats for fighter aircraft. She alleges that the company overcharged for

### Physics: Current Amps being Conducted on a Wire

If a 2.99 meter length of uniform conducting wire contains 5.1 * 10^18 current-carrying electrons, then if the electrons drift along the wire at .062 m/s, how many electrons per second pass a given point on the wire? What then is the current in amps?

### What charge must be placed at the empty corner?

See attached file for drawing. In the rectangle in the drawing, a charge is to be placed at the empty corner to make the net force on the charge at corner A point along the vertical direction. What charge (magnitude and algebraic sign) must be placed at the empty corner?

### Current Electricity: Current Density

1. Two wires both carry the same current (I). The moving charged particles in both wires are electrons, but the concentration of moving electrons in wire #1 is double the concentration of moving electrons in wire #2. Under what circumstances will the drift speed of electrons be the same in both wires? Choose the answer that b

### Four problems on electric field, charge, flux, charge density

1. A conducting rod of radius R1 = 1.57mm and length l=13.9m inside a thin-walled coaxial conducting cylindrical shell of radius R2=13.0R1 and the (same) length l. The net charge on the rod is Q1= +3.43 x 10^-12C; that on the shell is Q2= -2.32Q1. a) What is the magnitude and direction [radially inward or outward] of th

### How To Bend Water with Static Electricity

Title: How To Bend Water with Static Electricity Need simple Purpose Simple Hypothesis Material and Procedure Used Research Information to include: Introduction, Body, and Conclusion Introduction should restate your questions, and summerize the purpose of the experiment. It should also identify the scientific concep

### Calculate the electric potential and electric field at various points along the central axis of a circular disk.

Please refer to the attachment for more details (figures and hints) on the question. Consider a circular disk with radius R that has a uniformly distributed surface charge of Q. (a) Calculate the electric potential (Phi) at various points along the central axis of this disk. (b) Use the result of part (a) to determine t

### What is the potential at a point on the ring's central axis that is 10 cm from the ring's center?

Imagine that you have a ring 10 cm in diameter that has a uniformly distributed charge of 11 nC. What is the potential at the center of the ring (in volts)? What is the potential at a point on the ring's central axis that is 10 cm from the ring's center?

### Electric field due to a charged wire

Calculate the components of the electric field at the point P shown in figure E2.9. Assume that the charge Q is uniformly distributed over the wire. Please refer to the attachment for the mentioned figure.

### Magnetic field due to electric current

A straight wire is carrying current along the x-axis in the +x direction. A second straight wire is carrying an equal current along the y-axis in the +y direction. Both of the wires are in the x-y plane, and all questions pertain only to the magnetic field at points in the x-y plane. Which of the following statements are true ab

### Charges along sphere's equator: Electric potential at the origin

A sphere with radius 110.7 cm has its center at the origin. Equal charges of 7.3 &#956;C are placed at 90o intervals along the equator of the sphere. What is the electric potential at the origin? Please solve and explain problem.

### Magnitude of net electric force exerted on charge due to charges

Twelve identical point charges (q = 9.5 μC) are equally spaced around the circumference of a circle of radius 17.1 cm (like the numbers on the face of a clock). If the charge that is located at the 3 o'clock position is moved to the center of the circle, what is the magnitude of the net electric force exerted on this charge due

### NASA tele-transporter, magnetic field direction, generator, motor

1. Two test charges suspended in vacuum attract each other with a force of 1x10-6 N. What will the attractive force be if the vacuum is replaced with water at 20o C? The permittivity of water at this temperature is 7.07x10-10 C2/N-m2. 2. Three test charges, each with a charge of +1x10-6 C, are located at the points of an eq

### Physics: Three charges on a line, find direction and magnitude of net force

Part 1 Three charges, Q1, Q2, and Q3 are located in a straight line. The position of Q2 is 0.235 m to the right of Q1. Q3 is located 0.125 m to the right of Q2. The force on Q2 due to its interaction with Q3 is directed to the..... Right if the two charges are negative. A: True B: False Right if the two charges have o

### Capacitance, charge, area related physics questions

1) A capacitor has a charge of 0.002C when it is connected across a 100V battery, Find its capacitance. 2) A capacitor has a capacitance of 6.40uF. How much charge must be removed to lower the potential difference of its plate by 50.0V? 3) The plates of a parallel-plate capacitor have areas of 40cm2 and are separated by 0.2mm

### Electric force on a point charge

The answers are given, but no workings. *I only need solutions for these * 1. What is the magnitude of the force on a change of +2 x 10-7C that is 0.3m from a charge of -5 x 10-7C? Answer: 10-2N attractive force. 2. Two electrons repel each other with a force of 10-8N. How far apart are they? Answer: 1.5 x 10-10m 3

### Current due to a moving charge

Swirling Charged Ball A small sphere that carries a charge of 6.70 nC is whirled in a circle at the end of an insulating string. The angular speed is 111pi rad/s. What average current does this rotating charge represent?

### Electric Field Due to Two Charges

What is the the electric field at a point midway between a -7.72 mC and a +5.73 mC charge 3.20 cm apart? Take the direction towards the positive charge to be positive. Please explain the problem in details.

### Physics: Force on a Charge Due to an Electric Field

What is the electric force (with direction) on an electron in a uniform electric field of strength 3310 N/C that points due east? Take the positive direction to be east. -Please explain the problem

### Find the coulomb force on a point charge

Calculate the Coulomb force on q1 (q1 on left, q2 in the middle, q3 on the right). Choose forces to the right be positive and forces to the left negative. Assume q1 = 1.51 &#61549;C, q2 = 6.24 &#61549;C and q3 = -2.22 &#61549;C. r1 = 2.87 cm (distance between q1 and q2) and r2 = 1.88 cm (distance between q2 and q3).

### Charge on non-conducting spheres

Two small nonconducting spheres have a total positive charge of 737.4 microC. When placed 1.08 m apart, the force each exerts on the other is 15.4 N and is repulsive. What is the (larger) charge on the spheres? What if the force were attractive? What is the larger charge on one of the spheres?

### Net Force exerted on a Charge

A 5.61E-9 C charge is on the x axis at x = -1.39 m and a 2.11E-9 C charge is on the x axis at x = 1.88 m. Find the net force exerted on a 3.14E-9 C charge located at the origin. --Please explain each step.