Fluor Bulb
Fluor Bulb
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 Exo Terra Reptile Repti Glo 50 Compact Fluor Bulb 26W $12.99 Time Remaining: 14d 8h 53m Buy It Now for only: $12.99 Buy It Now |
 Exo Terra Reptile Repti Glo 100 Compact Fluor Bulb 13W $12.99 Time Remaining: 5d 22h 51m Buy It Now for only: $12.99 Buy It Now |
 Exo Terra Reptile Repti Glo 20 Compact Fluor Bulb 26W $12.99 Time Remaining: 4d 21h 28m Buy It Now for only: $12.99 Buy It Now |
 Exo Terra REPTI GLO 50 Compact Fluor Light Bulb 13W PT2186 $11.99 Time Remaining: 16d 10h Buy It Now for only: $11.99 Buy It Now |
 Exo Terra Reptile Repti Glo 50 Compact Fluor Bulb 13W $12.99 Time Remaining: 7d 9h 58m Buy It Now for only: $12.99 Buy It Now |
 Hagen Glo Electronic Ballast Light Kit T5 HO 2x24W 39W $44.99 Time Remaining: 21d 10h 35m Buy It Now for only: $44.99 Buy It Now |
 Hagen Glo Electronic Ballast Light Kit T5 HO 2x54W $44.99 Time Remaining: 5d 21h 43m Buy It Now for only: $44.99 Buy It Now |
 Exo Terra REPTI GLO 20 Full Spectrum Compact Fluor Light Bulb 26W PT2191 $11.99 Time Remaining: 16d 9h 55m Buy It Now for only: $11.99 Buy It Now |
 Reptile Lighting ReptiSun 50 UVB Fluor Bulb 36 T8 $25.95 Time Remaining: 16d 5h 3m Buy It Now for only: $25.95 Buy It Now |
 4 of Hagen Glo Electronic Ballast Light Kit T5 HO 2x54W $171.96 Time Remaining: 28d 11h 39m Buy It Now for only: $171.96 Buy It Now |
 Coralife 36 Inch Aqualight Compact Fluor Retrofit Kit $105.00 Time Remaining: 29d 4h 28m Buy It Now for only: $105.00 Buy It Now |
 Reptile Lighting ReptiSun 50 UVB Fluor Bulb 36 Case $239.99 Time Remaining: 6d 44m Buy It Now for only: $239.99 Buy It Now |
 Reptile Light ReptiSun 50 UVB Fluor Bulb 24 Lot of 12 $239.99 Time Remaining: 6d 41m Buy It Now for only: $239.99 Buy It Now |
 13 50 50 COMPACT FLUOR REPLACEMENT BULB 6 FOR ECLIPSE 12 1 PACK POWER COMPACT $15.16 Time Remaining: 2d 10h 45m Buy It Now for only: $15.16 Buy It Now |
 SUNGLOW 50 UVB COIL COMPACT FLUOR BULB 1 PACK REPTILE INCANDESCENT BULBS FLU $25.85 Time Remaining: 4d 1h 43m Buy It Now for only: $25.85 Buy It Now |
 13W 10000K COMPACT FLUOR REPLACEMENT BULB 6 FOR ECLIPSE 12 1 PACK POWER COM $15.16 Time Remaining: 2d 10h 45m Buy It Now for only: $15.16 Buy It Now |
 SUNGLOW 100 UVB COIL COMPACT FLUOR BULB 1 PACK REPTILE INCANDESCENT BULBS FL $27.85 Time Remaining: 4d 1h 43m Buy It Now for only: $27.85 Buy It Now |
Incandescent vs. Fluorescent price help?
With the information:
1 k Watt - hr = 5 cents
Incand.= $1.49 to buy at 100 W
Fluor.=$13.99 to buy at 15 W
How long do incandescent and fluorescent light bulbs have to run for the fluorescent light bulb to be equal in price to the incandescent light bulb at that time?
How do I do this?
Write out the equations that describe the cost of of running each type of bulb for a given number of hours.
Make the equations equal to each other and then solve to find the number of hours.
Cost for per watt per hour = 0.005 cents
Cost of an incandescent bulb (in cents) = 149 + 0.005*100*t
where t is the number of hours the bulb is run for.
Cost of a fluorescent bulb = 1399 + 0.005*15*t
At the time when they have both cost the same to run these two must be equal.
149 + 0.005*100*t = 1399 + 0.005*15*t
0.5*t - 0.075*t = 1399 - 149
0.425*t = 1250
t = 2941 hours.
2941/24 = 122.5 days