Chapter 33 Flashcards
(73 cards)
What type of field is the force field that surrounds a mass?
a gravitational field
What type of path does a ball take when you throw it in the air?
a curved path
In earlier chapters, what was the explanation for a curved path?
there is an interaction between the ball and earth - between their centers of gravity
What idea bothered Isaac Newton and others?
The idea that things not in contact could exert a force on tings without touching them.
Why does a ball curve?
The ball interacts with Earth’s gravitational field
What causes a field?
The mass of an object.
Just as the space around Earth and every other mass is filled with a __________ field, the space around every electric charge is filled with an __________ field.
gravitational; electrical
What is an electric field?
a force field that surrounds an electric charge or group of charges.
What does an electrical force hold in place?
an electron in orbit about a proton.
There is no contact between the objects, and the forces are…
acting at a distance
The satellite and electron interact with the _____ _____ of the planet and the proton and are everywhere in ______ with these fields.
force; fields; contact
The force that one electric charge exerts on another can be described as the…
interaction between one charge and the electric field set up by the other
An electric field has both magnitude and direction. True or False?
True
The magnitude (strength) of an electric field can be measured by…
its effect on charges located in the field
Where the force is greatest on the test charge (a small positive test charge), the field is ________. Where the force on the test charge is weak, the field is ______.
strongest; small
The direction of an electric field at any point, by convention, is…
the direction of the electrical force on a small positive test charge placed at that point
If the charge that sets up the field is positive, the field…
points away from that charge
An electric field is a scalar quantity. True or false?
false, it is a vector quantity
The magnitude of the field is indicated by…
the length of the vectors.
The electric field is greater where…
the vectors are long than it is where the vectors are short.
You can use electric field lines (also called lines of force) to represent an electric field. Where the lines are ______ apart, the field is weaker.
farther
For an isolated charge, the lines extend to…
infinity
For two or more opposite charges, the lines…
emanate from a positive charge and terminate on a negative charge
Why is the occupant in the car and the car safe when it was struck by lightning?
The electrons that shower down upon the car are mutually repelled and spread over the outer metal surface, finally discharging when additional sparks jump from the car’s body to the ground. The configuration of electrons on the car’s surface at any moment is such that the electric fields inside the car practically cancel to zero. This is true of any charged conductor.
