AP Physics C 2017

this up on the constant sheet):

Now the proton:

And finally the neutron:

F = (0  C)(60   N/C)    =   0   N

Notice that the proton feels a force in the direction of the electric field, but the electron feels the same
force in the opposite direction.
Don’t state a force with a negative sign. Signs just indicate the direction of a force, anyway. So, just
plug in the values for q and E , then state the direction of the force in words.

Electric Potential

When you hold an object up over your head, that object has gravitational potential energy. If you were to
let it go, it would fall to the ground.
Similarly, a charged particle in an electric field can have electrical potential energy. For example, if
you held a proton in your right hand and an electron in your left hand, those two particles would want to
get to each other. Keeping them apart is like holding that object over your head; once you let the particles
go, they’ll travel toward each other just like the object would fall to the ground.
In addition to talking about electrical potential energy, we also talk about a concept called electric
potential.

Electric    Potential: Potential    energy  provided    by  an  electric    field   per unit    charge; also    called  voltage

Electric potential is a scalar quantity. The units of electric potential are volts. 1 volt = 1 J/C.
Just as we use the term “zero of potential” in talking about gravitational potential, we can also use that
term to talk about voltage. We cannot solve a problem that involves voltage unless we know where the
zero of potential is. Often, the zero of electric potential is called “ground.”
Unless it is otherwise specified, the zero of electric potential is assumed to be far, far away. This
means that if you have two charged particles and you move them farther and farther from each another,