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exitwound
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Homework Statement
30. (a) Given the electric field of the earth: -150 N/C k, determine the potential difference from the floor to the ceiling, a distance of 3.0 m. (b) As a positive charge moves from the floor to the ceiling does it gain or lose potential energy? (c) As a positive charge moves from the floor to the ceiling does the electric field do positive or negative work? (d) How about a negative charge?
Homework Equations
[tex]V_f-V_i=\int \vec{E}\cdot d\vec{s}[/tex]
The Attempt at a Solution
a.) [tex]\Delta V=-Ed[/tex]
[tex]\Delta V=150(3)=450V[/tex]
b.)Electric Potential is electrostatic potential energy per unit charge, so if the potential difference becomes positive, the potential energy of the positive charge should become more positive as well. Correct? Anyone enlighten me with a better answer?
c.) (I've always had trouble with energy problems. I can't wrap my head around how objects can be related to PE and KE.) In this case, The work that has to be done to move a charge from floor to ceiling would be the amount of change of potential energy, correct? I don't understand why the answer is negative though. Anyone help on this one?
d.) Answers should be opposite of the positive charge, but I don't understand why.