Storing Electrical Energy 4 1 5 Electrical Potential
- Slides: 8
Storing Electrical Energy 4. 1. 5 Electrical Potential (Voltage)
Electrical PE + + To increase PE To decrease PE + + - +
Calculating Potential Difference • Amount of potential difference: • WORK DONE PER UNIT CHARGE • 1 VOLT = 1 J/C
Example #1 • 6. 0 joules of work are done in pushing an object with +3. 0 coulombs of charge toward a charged plate. – What type of charge does the plate have on it? – How much potential energy was stored in the electric fields? – How much electrical potential was generated? Positive 6. 0 J V = W/q V = 6. 0 J / 3. 0 C V = 2. 0 V
Example #2 • An object with a 2. 0 coulomb charge is accelerated through a potential difference of 10 volts. – How much kinetic energy does the object gain? V = W/q W = Vq W = (10 V)(2. 0 C) = 20 J
Electron-volts • Alternate unit for work/energy: • Raises 1 e to an electrical potential of 1 V • 1 e. V = 1. 6 x 10 -19 J What is is the energy needed to to raise four two What electronsto toaapotentialof of 2. 5 1. 0 volts? volt? electrons V = W /q 1. 0 V = W / 4 e 2. 5 2 e W = 2. 0 e. V 10 e. V
Example #3 • An electron travels a distance of 2. 0 x 10 -3 meter as its electrical potential is raised by 300 volts. – How much work is done on the electron? V = W/q 300 V = W / 1 e 300 V = W / 1. 6 x 10 -19 C W = 300 e. V W = 4. 8 x 10 -17 J
End of 4. 1. 5 - PRACTICE
