APES Math-2
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Mathematics
Date
Apr 3, 2024
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Uploaded by MinisterMinkMaster172
APES Math Use the following conversion factors. Answer using dimensional analysis. You MUST show your work. 1 cal = 4.184 J
1 C = 1000 cal
1 Btu = 1055 J
1 kWh = 3,600,000 J 1.
27 J = ___
_6.45_
______ cal 27/4.184= 6.45 2.
27 J = ___
_0.00645__
_____ C 6.45cal/1000C= 0.00645 3.
950 cal = ___ 3974.8_
_____ J 950 x 4.184= 3974.8 a.
125 kW = ___ 125,000_
______ w 125 x 1000= 125,000 4.
1376 bacon strips = ___
_4.74_
_______ pigs (290 bacon strips = 1 pig) [Those numbers are completely fictious…probably] 1376/ 290= 4.74 5.
84 J = __
__0.079_
________ Btu 84/1055= 0.079 6.
420 Btu = ___
443,100_
_________ J 420 x 1055= 443,100 7.
55 cal = ___
__0.23_
________ kJ 55 x 4.184= 230.12/1000 = 0.23 8.
60 w = __
___ 0.06
__________ kW 60/1000= 0.06 9.
230 Btu = _____ 57994_
______ cal 230 x 1055j= 242,650 j 242,650/ 4.184= 57994
10. 940 kcal = ___
_3.727_
________ Btu 11.
80 km/h = _______
3727.7_
____mph 12. 25 mph = __
0.00694__
_________ m/s 25 x 13. 600 kW = _____
3.6m_
_______ J = _________________ kJ 14. 120,500 kW = ____
_120.5
________ MW 15. How many miles will light travel in one year? (Light travels at a speed of ~300,000,000 m/s.) 300,000,000 m/s = _
5.88 trillion
_ miles 16. If the closest star to Earth (other than our Sun) is 4.2 light years away, how many miles from Earth is that star? 2.45 trillion miles Energy = power x -me power = Energy / -me Power units = wa6s Energy Units = kWh kWh= wa6 x -me 17.
A 615-watt refrigerator runs 24 hours/day. Calculate the energy usage.
Energy = watts x time Energy = 615 x 24= 7380kwH 18.
What is the cost to run the refrigerator in problem 18 for one year if the cost of electricity is 8 cents per kWh.
cost- 8 cents per kWh
Cost 2- ? Time- one year 7380 x 8 = 59,040 19. A 750-Watt hairdryer is used for 15 minutes. Calculate the Kwhr used. Energy = 750 x 15 = 11,250 kwh 20. From questions #20, calculate the cost to use the hair dryer 15 min. every day for one month @ 10 cents/
kWh. (Use 1 month = 30 days) 15 x 30 = 450 minutes / 60 = 7.5 hours 0.10 x 7.5 = 0/75 c 21. A family is considering external lighting for their home. The landscaper is recommending 20, 8-watt LED lights. The lights will be used for 8 hours a day. What is the cost to run the lights for an entire year if electricity costs 10.9 cents/kWh. 20 x 8 = 160 watt 8 hr/ day 160 x 8 hr = 1,280 kwh/ day 1,280 x 365 = 467,200 22.
The total wind power capacity in the United States in 2000 was about 2540MW. By 2015, the total wind power capacity in the United States was about 72,500MW. Calculate the percent change in the total wind power capacity in the United States from 2000 to 2015. 20754.33% increase 23. If electricity costs $0.20 per kilowatt hour, calculate the cost to run a 1500-watt appliance for two hours.
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kwh= power x time kwh= 1500 x 2= 3000 3000 x 0.20 = 600 24. Last year, I had I had 172 students in all my classes. This year, I have 162 students in all my classes. What is the percent decrease in the population of the classes I teach? 162- 172/172 x 100 = -5.81% 25. Your car gets 15 miles per gallon and your friend’s car averages 50 mpg. You decide to head off to Corbin, KY on vacation, 564 miles away. If gas costs $3.03/gallon and you decide to split the gas costs, how much money will you save by driving your friend’s car? 564/ 15 = 37.6 564/50= 11.28 37.6 - 11.28 = $26.32