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andrey2020 [161]

2 years ago

10

A swimming pool heater has to be able to raise the temperatureof the 40,000 gallons of water in the pool by 10 degress Celsius.H

ow many kilowatt-hours of energy are required? (one gallon ofwater has a mass of approximately 3.8kg and the specific heat ofwater is 4186 J/kg C)
a.) 1960 kWh
b.) 1770 kWh
c.) 330 kWh
d.) 216 kWh

1 answer:

andrew11 [14]2 years ago

3 0

Answer:b)1770 kWh

Explanation:

Given

volume of water $V=40,000 gallons$

Temperature rise $\Delta T=10^{\circ}C$

$c=4186 J/kg-^{\circ} C$

also 1 kg mass is approximately is 1 gallon

therefore 40,000 gallon is equivalent to 3.8\times 40000 kg

heat Required to raise temperature is

$Q=mc\Delta T$

$Q=3.8\times 40000\times 4186\times 10$

$Q=63,627.2\times 10^5 J$

$Q=63,672.2\times 10^2 KJ$

$Q=1767.42 kWh\approx 1770 kWh$

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How much heat is released when 432 g of water cools down from 71'c to 18'c?

maria [59]

The heat released by the water when it cools down by a temperature difference $\Delta T$ is
$Q=mC_s \Delta T$
where
m=432 g is the mass of the water
$C_s = 4.18 J/g^{\circ}C$ is the specific heat capacity of water
$\Delta T =71^{\circ}C-18^{\circ}C=53^{\circ}$ is the decrease of temperature of the water

Plugging the numbers into the equation, we find
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A photon is scattered from an initially stationary electron within a metal. How does the frequency of the photon change upon sca

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Compton scattering results in a reduction of the energy of the photon and hence an increase in the wavelength (from λ to λ') of the photon known as Compton effect.

Therefore, since the wavelength increases, we have from

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2 years ago

Water flowing through a cylindrical pipe suddenly comes to a section of pipe where the diameter decreases to 86% of its previous

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Answer:

Explanation:

The speed of the water in the large section of the pipe is not stated

so i will assume 36m/s

(if its not the said speed, input the figure of your speed and you get it right)

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so,

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1 year ago

The eiffel tower has a mass of 7.3 million kilograms and a height of 324 meters. its base is square with a side length of 125 me

uranmaximum [27]

Since the tower base is square with a side length of 125 m,

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1 year ago

Water flows without friction vertically downward through a pipe and enters a section where the cross sectional area is larger. T

djverab [1.8K]

Answer:

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6 0

2 years ago