Vocabulary
This states that the net amount of electric charge produced in any process is zero.
What is the law of conservation of electric charge?
Two negative charges___________each other.
What is repel?
This is the unit of charge.
What is the Coulomb?
The electric field is pointed _________ a positively charged particle.
What is toward?
The equation needed to solve:
A positive charge of +20.0e has an electron that is 1.00 x 10-9 m from it. What is the magnitude of the force on the electron?
F = kQ1Q2/(r^2)
Materials in which the electrons are bound very loosely to the nuclei and can move about freely within the material are referred to as ___________.
What is a conductor?
Describe the model of the atom.
The positively charged _________ and the negatively charge,___________, always _______ each other.
An atom, mostly empty space, have a central nucleus with protons and neutrons. Electrons are negatively charged, and distribute themselves in regional "clouds" around the nucleus.
protons, electrons, attract
These are the units for an electric field.
What are N/C?
What is the equation you need to solve for the magnitude of this
What are the magnitude and direction of the electric field at a distance of 1.50 m from a 50.0-nC charge?
E = kQ/r^2
This is an intermediate category of a few material that allow a medium amount of excess charge to move across its surface.
What are semiconductors?
A glass rod is rubbed with a piece of silk. During the process the glass rod acquires a positive charge and the silk acquires a ____________ charge.
What is a negative charge?
What are the units of the electric proportionality constant, k?
What are N m^2/C^2.
Draw field lines from a positive charge, Q, to a negative charge 2Q.
See picture
This is the equation you need to solve this problem:
A 2.0 μC charge is placed at the 0 cm mark of a meter stick and a -3.0 μC charge is placed at the 20.0 cm mark. What is the magnitude & direction of the electric field at the 15.0 cm mark?
What is:
E=(kQ1/r^2)+(kQ2/r^2) for the magnitude & the
direction is toward the negative charge
This type of molecule is neutrally charged but the charge is not uniformly distributed, like in water, allowing excess charge to attach to these types of molecules.
What are polar molecules?
A negatively charged rod is brought near one end of an uncharged metal bar. The end of the metal bar farthest from the charged rod will now have a _________ charge.
What is a negative?
This is the charge of a single electron.
What is 1.602 x 10^-19 C?
Two charged objects are separated by a distance d. The first charge is larger in magnitude than the second charge. Describe the forces they exert on each other.
They are equal and opposite.
What equation is required to solve this problem:
A force of 10 N acts on a charge of 5.0 μC when it is placed in a uniform electric field. What is the magnitude of this electric field?
What is F = qE; specifically arranged to solve for
E = F/q
An atom that has more electrons than protons is called a negative ________.
What is an ion?
Describe two ways a metal rod, originally neutral, can be permanently charged by induction.
What are:
The charged rod will cause the neutral rod's charges to separate. While the charged rod is still present, you must either:
1. break the rod in the middle.
2. Attach it to ground, allowing extra electrons to move. Then detach the grounding wire before removing the charged rod causing the induction.
This is the mass of an electron (at rest).
What is 9.11 x 10^-31?
Draw the electric field generated from a single negative charge.
Place a negative test charge 2 cm from the charge. Draw the Force vector exerted on the test charge.
see picture
What are the steps to solving this problem:
Three identical charges of 5.0 μC are placed at the vertices of an equilateral triangle which measures 15 cm on a side. What is the magnitude of the electrostatic force which acts on any one of the charges?
1. Draw a picture with the charges and force vectors.
2. Calculate the magnitude of each force acting on the chosen charge.
3. Break down any vector not on an axis into its components.
4. Add the x/y components of all vectors to get the x/y components of the net force (an x/y chart is helpful here to ensure proper addition of all components and correct signs for direction.
5. Use Pythagorean theorem to calculate the magnitude of the net force vector.
6. Use geometry or trig to calculate angle.