How to visualize a potential difference?
Problem:
A proton (at rest) is accelerated through a potential difference of 100 v, and it gains speed... how can I picture this in my head so i can understand it?
My idea:
Potential difference is the difference between two points a and b. So the proton is traveling from point a (where the potential is 0) to point b (where the potential is 100). But what doesn't add up is... if the proton is going towards a higher potential, then it must be gaining potential energy and losing kinetic energy; but the question above says it gains speed... which means the kinetic energy is increasing.
Solution:
In the question above, we weren't told whether the origin of the proton is at a higher or lower potential than the destination.
The only way the proton can gain speed is if and only if and only if the destination is at a lower electric potential than the origin.
Had this problem been about an electron, which recall is negatively charged, we would need to conclude the exact opposite, such that the destination is at a higher electric potential than the origin.
Remember: if electric potential is the height of a "hill" at every location in space, protons and cations "want to go downhill" whereas electrons and anions "want to go uphill".
A proton (at rest) is accelerated through a potential difference of 100 v, and it gains speed... how can I picture this in my head so i can understand it?
My idea:
Potential difference is the difference between two points a and b. So the proton is traveling from point a (where the potential is 0) to point b (where the potential is 100). But what doesn't add up is... if the proton is going towards a higher potential, then it must be gaining potential energy and losing kinetic energy; but the question above says it gains speed... which means the kinetic energy is increasing.
Solution:
In the question above, we weren't told whether the origin of the proton is at a higher or lower potential than the destination.
The only way the proton can gain speed is if and only if and only if the destination is at a lower electric potential than the origin.
Had this problem been about an electron, which recall is negatively charged, we would need to conclude the exact opposite, such that the destination is at a higher electric potential than the origin.
Remember: if electric potential is the height of a "hill" at every location in space, protons and cations "want to go downhill" whereas electrons and anions "want to go uphill".
-kosong-
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