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VladimirAG [237]

3 years ago

12

He wild horse was once short and slow to run from predators, yet today it is tall and runs very quickly, thus making it able to

escape from predators. What caused this change?

1 answer:

LenKa [72]3 years ago

6 0

The growth and development-

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a water heater contains 58 Gal of water. How many kilowatt-hours of energy are necessary to heat the water in the water heater b

Citrus2011 [14]

Answer:

6.45 KWh

Explanation:

Data given:

amount of water = 58 gallon

Convert gallons to L

1 gallon = 3.78541 L

58 gallon = 58 x 3.78541 = 220 L

change in temperature = 25 °C

kilowatt-hours of energy = ?

Solution:

First we have to change volume of water into mass

following formula will use

m = d x v . . . . . . (1)

as we know

density of water = 1000 g/L

Put values in equation 1

m = 1000 g/L x 220 L

m = 220000

To calculate heat we use following formula

Q = m.c.ΔT . . . . . . . . . . (2)

Where

m= mass

c = specific heat of water

specific heat of water = 4.186 J/g °C

ΔT = change in temperature

Put values in equation 1

Q = 220,000 g x 4.186 J/g °C x 25 °C

Q = 23023000 J

As we need this value in kilowatt-hours of energy so we convert J to KWh

1 J = 2.8 x 10⁻⁷ KWh

23023000 J = X KWh

Do cross multiplication

KWh = 23023000 J x 2.8 x 10⁻⁷ KWh / 1 J

KWh = 6.45 KWh

6.45 KWh (kilowatt-hours) of energy are needed to heat the water in the water heater.

3 0

3 years ago

Helpe pls I will mark brainlest

olya-2409 [2.1K]

Answer:

What is the question needing to be answered?

Explanation:

Usually with a scientific hypothesis, you ask the question in an if, then statement. For example: If it rains outside, then the ground will be wet. It's kind of like a cause and effect statement.

4 0

3 years ago

Hi can you slove this please. ..

Crank

Answer : The balanced chemical equation will be:

(i) $2K+H_2SO_4\rightarrow K_2SO_4+H_2$

(ii) $Mg(OH)_2+Zn\rightarrow Zn(OH)_2+Mg$

Explanation :

Balanced chemical equation : It is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.

Part (i):

The balanced chemical equation will be:

$2K+H_2SO_4\rightarrow K_2SO_4+H_2$

This reaction is a single displacement reaction in which most reactive element (potassium) displaces the least reactive element (hydrogen) form their solution.

Part (ii):

The balanced chemical equation will be:

$Mg(OH)_2+Zn\rightarrow Zn(OH)_2+Mg$

This reaction is a single displacement reaction in which most reactive element (zinc) displaces the least reactive element (magnesium) form their solution.

7 0

3 years ago

What is the amount in moles of a 52 g sample of aluminium fluoride, AIF3

Karo-lina-s [1.5K]

Answer:

Try looking for some kind of answer that has to do with .61904

Explanation:

52 g x 1 mol/ (molar mass of aluminum fluoride) 84 g = .619047619

Sorry if this is wrong but that's my best guess

6 0

2 years ago

Which atom is most likely to accept electrons to form an ionic bond?

Alinara [238K]

Halogens (atoms with 7 valence electrons) and Hydrogen

or generally, atoms with their shells almost full

5 0

3 years ago