Who Killed the Electric Car? Video from Friday Worksheet due on Tuesday

Topic 6,7,8 Test Wednesday April 22nd Multiple Choice Written Response Topic 6: everything including drawing diagrams of generators and motors Topic 7: everything including full response math questions (formula, substitute, solve) Bring your calculator! Topic 8: everything including higher-order thinking attitudes

Topic 7: From the Grid to Your Home Residential Step down Transformer Substation: Step up Transformer Distribution Station

Investigation Page 334 in your textbook How efficient is coal, really? Topic 8 Investigation Page 334 in your textbook How efficient is coal, really? Calculate the percent of energy from coal that ends up giving you light from an incandescent bulb Start with 1 million joules = 1 x 106 = 1 000 000 J 99% x 97% x 33 % x 85% x 15%

What is more efficient, really? Topic 8 What is more efficient, really? Incandescent light bulbs Fluorescent light bulbs Take notes on the 12 minute video because you will be asked a related question on your test. https://www.youtube.com/watch?v=3gjvOOlHmsU

REVIEW E = P x t is the formula on your PAT Be able to use it for Joules = Watts x sec kWh = kilowatts x hours P = E/t t = E/P P = I x V is the formula on your PAT Be able to manipulate it for: I = P/V V = P/I

Calculate power P = I x V What is the power, in Watts, of an electronic device that allows 3 A of current when plugged into a 120V socket?

Calculate power Answer What is the power, in Watts, of an electronic device that allows 3 A of current when plugged into a 120V socket? P = I x V P = 3A x 120V P = 360 W

Find Current What is the current in an 80 W light bulb in a 120V socket? P = I x V

Find Current Answer What is the current in an 80 W light bulb in a 120V socket? P = I x V P/V = I x V/V I = P ÷ V I = 80 W ÷ 120 V I = 0.67 A

Find Voltage What is the voltage of a 110 W device with 4A? P = I x V

Find Voltage Answer What is the voltage of a 110 W device with 4A? P = I x V P/I = I x V / I V = P ÷ I V = 110 W ÷ 4 A V = 27.5 V

Calculate energy E = P x t What is the energy input, in Joules, of a 60 W laptop charger that is plugged in for 45 minutes?

Calculate energy Answer E = P x t What is the energy input, in Joules, of a 60 W laptop charger that is plugged in for 45 minutes? E = P x t t = 45 x 60 = 2700 s E = 60W x 2700s E = 162,000 J

Calculate Efficiency Charger The 60 W laptop charger that is plugged in for 45 minutes outputs 98,000 J of useful energy to the laptop battery. How efficient is this charger?

Calculate Efficiency Answer The 60 W laptop charger that is plugged in for 45 minutes outputs 98,000 J of useful energy to the laptop battery. How efficient is this charger? E = P x t E = 60 W x (45x60) seconds E = 162,000 J Efficiency = output/input x 100% Efficiency = 98,000 J x 100% 162,000 J Efficiency = 60.5 %

Calculate Efficiency Lightbulb A 45 W lightbulb that is on for 90 minutes outputs 98,000 J of light energy. How efficient is this bulb?

Calculate Efficiency Answer A 45 W lightbulb that is on for 90 minutes outputs 98,000 J of light energy. How efficient is this bulb? E = P x t E = 45 W x (90x60) seconds E = 243,000 J Efficiency = output/input x 100% Efficiency = 20,000 J x 100% 243,000 J Efficiency = 8 %