IMathAS-libretexts

A student has an isolated system of charged particles. The student wants to calculate the change $\displaystyle Î”{U}_{{E}}$ in the electric potential energy of the system between two instants in time but cannot do that directly, since the student does not have any information about the magnitude of the charges. Which of the following correctly describes a mathematical routine, if any, that can be used to determine $\displaystyle Î”{U}_{{E}}$ ? Gravitational effects are negligible.

Calculate the change $\displaystyle Î”{K}$ in the total kinetic energy of the particles. This will be equal to âˆ’ $\displaystyle Î”{U}_{{E}}$ .
Calculate the change Î” $\displaystyle {K}$ in the total kinetic energy of the particles. This will be equal to $\displaystyle Î”{U}_{{E}}$ .
Calculate the average kinetic energy $\displaystyle {K}_{{{a}{v}{g}}}$ of the particles during the time interval between the two instants. This will be equal to $\displaystyle Î”{U}_{{E}}$ .
The change in electric potential energy of the system cannot be determined without knowing the magnitudes of the charges.

License