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3 years ago

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An uncovered swimming pool loses 1.0 inch of water off its 1,000 ft^2 surface each week due to evaporation. The heat of vaporiza

tion for water at the pool temperature is 1050 btu/lb. The cost of energy to heat the pool is $10.00 per million btu. A salesman claims that a S500 pool cover that reduces evaporation losses by two-thirds will pay for itself in one 15-week swimming season. Can it be true?

1 answer:

soldi70 [24.7K]3 years ago

3 0

Answer:

The affirmation is true, the cover will be worth buying

Explanation:

The equation necessary to use is

E = m*cv,

Where

cv: the heat of vaporization.

Finding the rate at which the water evaporates (m^3/week).

The swimming pool loses water at 1 inch/week off its 1,000 ft^2

Than,

1000 ft² * 1 in/wk * 1 ft/12 in = 83.33 ft³/week

To obtains the rate of mass loss it is necessary to multiply it for the density of water

83.33 ft³/week * 62.4 lb/ft³ = 5200 lb/week

Knowing the vaporization heat it is possible to find the rate of heat which is leaving the swimming pool

5200 lb/week * 1050 BTU/lb = 5460000 btu/week

Over a 15-week period, the pool loses 81.9 million BTU.

Knowing the cost of energy to heat the pool is $10.00 per million btu

The price = $819

This way, the affirmation is true, the cover will be worth buying

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KengaRu [80]

Answer:

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3 years ago

The air in a room has a pressure of 1 atm, a dry-bulb temperature of 24C, and a wet-bulb temperature of 17C. Using the psychrome

TEA [102]

Answer:

(a) Relative Humidity = 48%,

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3 years ago

A shunt regulator utilizing a zener diode with an incremental resistance of 8 ohm is fed through an 82-Ohm resistor. If the raw

spayn [35]

Answer:

$\triangle V_0=0.08V$

Explanation:

From the question we are told that:

Incremental resistance $R=8ohms$

Resistor Feed $R_f=82ohms$

Supply Change $\triangle V=1$

Generally the equation for voltage rate of change is mathematically given by

$\frac{dV_0}{dV}=\frca{R}{R_1r_3}$

Therefore

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3 years ago

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slamgirl [31]

Answer:

d. 90%

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3 years ago

Why do we care about a material's ability to resist torsional deformation?

lesya692 [45]

Answer:

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Explanation:

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The torsion is characterized geometrically because any curve parallel to the axis of the piece is no longer contained in the plane initially formed by the two curves. Instead, a curve parallel to the axis is twisted around it.

The general study of torsion is complicated because under that type of solicitation the cross section of a piece in general is characterized by two phenomena:

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5 0

3 years ago