The work energy theorem states: $$W = \int_i^f \mathbf{F}net\cdot d\mathbf{l} = \frac{1}{2}mv_f^2 - \frac{1}{2} mv_i^2$$ This theorem is valid: 1. only for conservative forces. 2. only for non-conservative forces. 3. only for forces which are constant in time 4. only for forces which can be expressed as potential energies 5. for all forces. Note: * Correct Answer: E

A + and - charge are held a distance R apart and released. The two particles accelerate toward each other as a result of the Coulomb attraction. As the particles approach each other, the energy contained in the electric field surrounding the two charges... <img src="./images/two_charges_coming_together.png" align="center" style="width: 600px";/> 1. increases 2. decreases 3. stays the same Note: * Correct Answer: B