Physics chapter 18
What is the unit for charge?
Coulomb or C
What is an electric field?
An electric field is an area where the electrical forces act on a charged object.
In the physics and electrical charges world what does the term ground mean? And why is grounding important?
A ground has an infinite supply of electrons and is useful for balancing out the charge of any charged object to make it neutral. Grounding is important because it causes neutralizes charges which could be dangerous in different situations.
A metal sphere is electrically neutral. It is touched by a positively charged metal rod. As a result, the metal sphere becomes charged positively. Which of the following occur during the process
Electrons are transferred from the sphere to the rod. The metal sphere loses electrons. The overall charge of the system is conserved.
In charged objects, which subatomic particle is actually moving from object to object?
Electrons. Protons and Neutrons are fixed to the nucleus and cannot move freely
What is electrostatic equilibrium?
Electrostatic equilibrium is what is reached when the charges are balanced out and no longer move (meaning that they are not moving toward or away from each other).
TRUE or FALSE: An object that becomes grounded gains neutrons during the grounding process
FALSE
What are the 3 different ways an object can become charged? How do they differ from one another?
Friction - in contact and surfaces are being rubbed together. Objects started out as being neutral and gain charge due to electron affinity Induction - a charged object is brought near a non charged object but does not touch it. Conduction - a charged object is touched to a non charged object and electrons are transferred.
What happens when a charged object comes into contact with a neutral object?
It is attracted to it since the electrons will move allowing for it to be attracted.
What does it mean for an object to be polarized?
It means that there is a positive charge on one side of the object and a negative charge found on the other side.
What do each of the variables in Coulomb's Law equation stand for?
K = a constant equal to 9x109 in air. It is a measure of air conductivity Q = the charges of two objects F = the electrical force between two objects D = the distances between the center of mass of two charged objects
Which statement best explains why a rubber rod becomes negatively charged when rubbed with fur?
Molecules in the rubber rod have a stronger attraction for electrons than the molecules in the fur.
What is the charge of a single electron?
Negative 1.6 x10-19 C
If the electrons move from the sweater to the balloon, which has a greater electron affinity? How can you tell?
The balloon does. Electron affinity means that the object attracts electrons to itself so if the balloon gains a negative charge, that means the electrons traveled from the sweater to the balloon because it has a higher affinity for the electrons.
What's the difference between a conductor and an insulator?
The electrons found in a conductive material are more free to move around than those found in an insulative material.
Define electrical force. Is it a vector? What is it measured in? Is it a contact force?
The force experienced by a charged object. This force can either attract or repel and depends on the charges involved. It is a vector Is is measured in Newtons, like all forces It is a long distance force
Where would you expect an electrical field vector to have the greatest strength?
When it is closer to the charged object
A neutral metal sphere is touched by a negatively charged metal rod. As a result, the sphere will be ____ and the metal rod will be ____. Select the two answers in their respective order.
negatively charged, negatively charged
