more q's about 3 physics formulas

[2010premed]

change in PE = kq1q2 (1/rf - 1/ri)
and for an electric dipole, T=pE sintheta
and PE= -PpE) cos theta
do I really need to know these?

can someone please clarify their concepts?

---

Members don't see this ad.

 

[starbaduk]

change in PE = kq1q2 (1/rf - 1/ri)
and for an electric dipole, T=pE sintheta
and PE= -PpE) cos theta
do I really need to know these?

can someone please clarify their concepts?

First equation you need to know for sure. It's just variation of E=qV.
As for electric dipole.... i don't recognize that equation. I would just know that dipole is directly proportional to E.

Don't recognize the last equation..