L4

Fundamental Formulas

1. Work ($W$)
   • General Work: $W = Fd$
   • Gravitational Work: $W = mgh$
   • Electrical Work: $W = (qE)d$
2. Potential Energy ($U$)
   • In a uniform field: $U = qEd$
   • Absolute Potential Energy: $U = -k\frac{Qq}{r}$
   • Change in Potential Energy: $\Delta U = U<em>B - U</em>A$
3. Electric Potential ($V$)
   • Definition: $V = \frac{U}{q}$
   • Potential from a Point Charge: $V = k\frac{Q}{r}$
   • Energy Relation: $U = qV$
4. Electric Field ($E$)
   • Definition: $E = \frac{F}{q}$

Key Values and Units

• Work/Energy: Measured in Joules ($J$); $1\text{ J} = 1\text{ N m}$.
• Electric Potential: Measured in Volts ($V$); $$1\text{ V} = 1\