[L1] Electric Potential

work

this is defined as the product of displacement (d) and a parallel applied force (f)

work

this is only done by a force on an object if that same force cause to move in the direction of the force

cause to move in the direction of the force

work is only done by a force on an object if that same force ____

(f*costheta)*d

the formula for work

work is positive

if force has a component in the direction of displacement, then work is ____

work is negative

if force has a component opposite to direction of displacement, then work is ____

no work

if force component is perpendicular to direction of displacement, then work is ____

energy

the ability to do work

potential energy (U)

it is defined as the ability to do work by virtue of position or condition

position or condition

potential energy is defined as the ability to do work by virtue of ____

kinetic energy (K)

it is defined as the ability to do work by virtue of motion (velocity)

motion (velocity)

kinetic energy is defined as the ability to do work by virtue of ____

field

a region of influence surrounding an object

consider the forces exerted on the ball. the force (F) does ____ work

negative

consider the forces exerted on the ball. the force (mg) does ____ work

decreases (since the field can do positive work if m is released)

the potential energy at b relative to a ____ because the field can do positive work if m is released

increases

the potential energy at a relative to b ____ because the field would need outside force to move m

work done

____ is equal to the change in the object's potential energy

potential energy

work done is equal to the change in the object's _____

positive, negative

electric field is always from ____ surface to ____ surface

negative work

consider the work done by the electric field to move the positive charge q from A to B, a vertical height r. the electric field does ____ work

increases

consider the work done by the electric field to move the positive charge q from A to B, a vertical height r. the electric field ____ in potential energy

gives work back

consider the work done by the electric field to move the positive charge q from A to B, a vertical height r. if released, the field ____

positive work

consider work done by the electric field to move the positive charge q from B to A, a vertical height r. the electric field does ____ work

decreases

consider work done by the electric field to move the positive charge q from B to A, a vertical height r. the potential energy ____

nothing happened

consider work done by the electric field to move the positive charge q from B to A, a vertical height r. if released, ____

positive work

when positive charge moves in the direction of the electric field, the field does ____ work on the charge

decreases

when positive charge moves in the direction of the electric field, the potential energy ____

negative

when positive charge moves opposite the direction of the electric field, the field does ____ work on the charge

increases

when positive charge moves opposite the direction of the electric field, the potential energy ____

positive work

consider work done by the electric field to move the negative charge q from A to B, a vertical height r. the electric field does ____ work on -q

decreased

consider work done by the electric field to move the negative charge q from A to B, a vertical height r. the potential energy is ____

consider work done by the electric field to move the negative charge q from A to B, a vertical height r. if released from b, nothing happens

negative work

consider work done by the electric field to move the negative charge q from B to A, a vertical height r. the electric field does ____ work on -q

increased

consider work done by the electric field to move the negative charge q from B to A, a vertical height r. the potential energy is ____

gives work back

consider work done by the electric field to move the negative charge q from B to A, a vertical height r. if released from a, the field _____

more work/energy is needed

how can you compare the amount of work or potential energy needed to move 1C of charge to that of 10C in an electric field

electric potential energy, u, of a charged particle at a point in an electric field region

____ is equal to the work done by the electric field to bring that point to a point of infinite distance

electric potential energy

this is the energy of a charge object due to its position in an electric field

only the endpoints

the work done by the electric force fo this path (epe of two-point charges) depends on ____

the path taken, distances ra and rb (distance between the two points)

the work done on charge qo by the electric field of charge q does not depend on ____, but only on ____

ra an rb (point charges), details of the path

the work done by q0 on the electric field e produced by q depends only on ____ and ____, not on the ____

positive

the potential energy is ____ if the charges q and q0 have the same sign

negative

the potential energy is ____ if the charges q and q0 have opposite signs

approaches positive infinity

if q and q0 have the same sign, as r approaches 0, u ____

approaches 0

if q and q0 have the same sign, as r approaches infinity, u ____

approaches negative infinity

if q and q0 have opposite signs, as r approaches 0, u ____

approaches 0

if q and q0 have opposite signs, as r approaches infinity, u ____

distances (r1, r2, r3)

the potential energy associated with a charge q0 at point a depends on other charges, q1, q2, and q3, and on their ____

fields due to the individual charges

the total electric field at each point is the vector sum of the _____

contributions from the individual charges

the total work done on q0 during any displacement is the sum of the ____

electric potential

the potential energy per unit charge associated with a test charge at that point

potential energy, unit charge

electric potential is the ____ per ____ associated with a test charge at that point

scalar

potential energy and charge are both ____ quantities, so potential is anlso ____

potential at point a, potential at point b

we call va and vb the ____ and ____ respectively

work done per unit charge

the ____ by the electric force when a charged object moves from a to b is equal to the potential at a minus the potential at b

potential at a minus the potential at b

the work done per unit charge by the electric force when a charged object moves from a to b is equal to the ____

vab, the potential (in v)

____ of a with respect to b, equals the work done (in j) done by the electric force when a unit (1 c) charge moves from a to b

a to b

vab, the potential (in v) of a with respect to b, equals the work done (in j) done by the electric force when a unit (1 c) charge moves from ____

b to a

vab, the potential (in v) of a with respect to b, equals the work (in j) that must be done to move a unit (1c) slowly from ____ against the electric force

vab, the potential (in v)

____ of a with respect to b, equals the work (in j) that must be done to move a unit (1c) slowly from b to a against the electric force

a potential of one volt

____ at a given point means that a charge of one coulomb placed at that point will experience a potential energy of one joule

a charge of one coulomb

a potential of one volt at a given point means that ____ placed at that point will experience a potential energy of one joule

potential energy of one joule

a potential of one volt at a given point means that a charge of one coulomb placed at that point will experience a ____

potential energy, unit charge

electric potential is the ____ per ____

voltage

also known as electric potential difference

electric potential difference

also known as voltage

voltage or electric potential difference

this is the difference of potential between two points

increases

in a positive point charge, voltage ____ as you move inward

decreases

in a positive point charge, voltage ____ as you move outward

decreases

in a negative point charge, voltage ____ as you move inward

increases

in a negative point charge, voltage ____ as you move outward

equipotential surface

it is a three-dimensional surface on which the electric potential (v) is the same at every point

electric potential (v)

an equipotential surface is a three-dimensional surface on which the ____ is the same at every point

mutually perpendicular

field lines and equipotential surfaces are always _____

it moves against the direction of electric field. if it doesn’t, the electric field does work on it (positive or negative)

work is only done on charge when ____