Answer:
ai) 73000 gal/yr
aii) $730 per year
b) 1000 days
Step-by-step explanation:
ai) The water usage per day is ...
(4 showers/day)(10 min/shower)(5 gal/min) = 200 gal/day
Then the usage per year is ...
(200 gal/day)(365 days/yr) = 73,000 gal/yr
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aii) The cost of electricity is the cost of heating half the water usage, so is ...
(0.20 kWh/gal)(1/2)(73,000 gal/yr)($0.10/kWh) = $730/yr
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b) The current daily cost of electricity for heating water is ...
($730/yr)/(365 days/yr) = $2/day
If the cost is cut in half, it will be $1 per day. That means the savings is $1 per day, so it will take 1000 days to recover the $1000 initial cost. (Effectively, the average cost for the first 1000 days is the same as if the water heater had not been replaced.)
Answer:
(x - 5)² + (y + 3)² = 16
Step-by-step explanation:
The equation of a circle in standard form is
(x - h)² + (y - k)² = r²
where (h, k) are the coordinates of the centre and r is the radius
here (h, k) = (5, - 3) and r = 4, so
(x - 5)² + (y - (- 3))² = 4², that is
(x - 5)² + (y + 3)² = 16
Answer:
Question 20 3 < c < 9
Question 21 2.5
Step-by-step explanation:
hope this helps u
Answer:
See explanation
Step-by-step explanation:
1. The first figure shows triangular prism. The volume of the triangular prism is
The base of this triangular prism is the triangle with the base of 7 cm and height of 
cm (it is not seen).
The base area is
and the volume of the prism is
Just substitute the length of the height and calculate the volume.
2. The second figure shows square pyramid. The volume of the square pyramid is
The base of this square pyramid is the square with the side length of 4 yd.
The base area is
and the volume of the pyramid is
