Respuesta :
Answer:
annual cost for electricity  for 100 W is $43.8
annual cost for electricity  for 25 W is $10.95
Explanation:
given data
electricity costs = $0.16 per kWâ‹…h
duration lamppost = 7.50 h per day
to find out
What is the annual cost for electricity  for 100 W and 25 W
solution
we know power consumption 1  day for 100 W  = 100 × 7.50
and power consumption in 1 year = 365×  100 × 7.50 = 273750 watt hour
and we know 1 watt hour = 0.001 Kw hour
so that  273750 watt hour = 273.750 KWh
and 1 kWh = $0.16
so 273.750 KWh = 0.16 × 273.750 = $43.8
annual cost for electricity  for 100 W is $43.8
and
power consumption 1  day for 25 W  = 25 × 7.50
and power consumption in 1 year = 365×  25 × 7.50 = 68437.5 watt hour
and we know 1 watt hour = 0.001 Kw hour
so that  68437.5 watt hour = 68.4375 kWhour
and 1 kWh = $0.16
so 68.4375 kWh = 0.16 × 68.4375 = $10.95
annual cost for electricity  for 25 W is $10.95
The annual cost of electricity to power the lamppost is $43.8.
The annual cost of electricity to power the fluorescent bulb is $10.95.
Total energy consumed
The total energy consumed is calculated as follows;
[tex]E_{lampost} = \frac{100}{1000} \times 7.5 \times 365 = 273.75 \ kWh\\\\E_{fluorescent} = \frac{25}{1000} \times 7.5 \times 365 = 68.44 \ kWh[/tex]
The cost of electricity to power the lamppost
[tex]Cost _\ {lampost}} \ = 273.75 \times 0.16 = \$ 43.8[/tex]
The cost of electricity to power the fluorescent bulb
[tex]Cost _\ {fluorescent}} \ = 68.44 \times 0.16 = \$ 10.95[/tex]
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