The power of electricity AWESOME Sin City Las

The power of electricity

AWESOME !!!!!

“Sin City”, Las Vegas, Nevada

Christmas with a vengeance!! UFO’s stopping by to see The pretty lights.

Last night’s homework Solve the following circuit problems: (USE ALL 6 STEPS!) 1. V=6 v I = 2 amps. R=? 2. V = 8. 5 v I=? R = 2. 125 Ω 3. V=? I = 9 amps. R = 10 Ω 4. The heater fan on the #33 bus is on a 7 amp. circuit. The bus has a 24 v battery. What is the resistance of the fan motor?

1. V=6 v I = 2 amps. R= ? R=? V=6 v I = 2 amps. V=Ix. R 6 v = 2 amps. x R 2 amps. = 2 amps. 6 v/2 amps. = R 3Ω=R

2. V = 8. 5 v I = ? R = 2. 125 Ω V = 8. 5 v I=? V=Ix. R 8. 5 v = I x 2. 125 Ω 8. 5 v/2. 125 Ω = I 4 amps. = I

3. V=? I = 9 amps. R = 10 Ω V=? I = 9 amps. V=Ix. R V = 9 amps. x 10 Ω V = 90 v

4. V = 24 v I = 7 amps. R=? V = 24 v I = 7 amps. V=Ix. R 24 v = 7 amps. x R 24 v/7 amps. = R 3. 429 Ω = R

Electrical Power • Electric Power – the rate at which electrical energy is used by a Load. • Units of power are the Watt (W) • A human climbing a flight of stairs is doing work at a rate of about 200 watts. U 3 e-L 2

Joule’s Law • James Joule (1818 – 1889) – showed that heat and electrical energy are interchangeable. • Joule’s Law: Power = Voltage x Current P=Vx. I Watts = Volts x Amperes U 3 e-L 1

Problems – Joule’s Law 2. Table P= V= I= 1. Diagram P= V= I= 3. Formula, solve P=Vx. I

A cell phone charger provides 5 volts (DC) to charge the cell phone. The amount of current that the charger delivers is. 7 Amperes. What is the power used by the cell phone in recharging its battery? P=? V = 5 v I =. 7 amps. P=? V = 5 v I =. 7 amps. P=Vx. I P = 5 V x. 7 A P = 3. 5 W

What is the resistance of the cell phone? V = I x R 5 v =. 7 amps. x R 5 v/. 7 amps. = R 7. 14 Ω = R

Formulae and calculations only! YEAAAAAAA! P = 25 W V = 100 v I=? R=? P=? V = 12 v I=? R=6Ω

P = 100 W V=? P = 1400 W V = 120 v (cont’d) I = 2. 5 amps. R=? I=? R=?

1. A Honda Insight (hybrid) has a 144 volt battery. The electric motor that the battery powers uses 20, 000 Watts of power. What is the current in this circuit? What is the resistance of the motor? ( 1 diagram, 1 table, 2 formulae, 2 calculations. )

2. A curling iron uses a 120 v power source (AC). The current in the circuit is 12. 5 amps. What is the power of the curling iron? What is the resistance of the curling iron? ( 1 diagram, 1 table, 2 formulae, 2 calculations. )

3. An electric fan has a power of 600 W. The voltage is 120 v (AC). What is the current in this circuit? What is the resistance of the fan motor? ( 1 diagram, 1 table, 2 formulae, 2 calculations. )