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viva [34]
3 years ago
9

How does a scientist explain something when a controlled experiment cannot be carried out

Chemistry
1 answer:
Romashka [77]3 years ago
7 0
<span> We look for evidence. There are numerous natural phenomenon that we can't observe happening in real-time because they happen over large time scales, or large spatial scales. But we can observe the effects of these phenomenon and make predictions about what other effects we should see. </span>
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In Charles's law, gas volume is directly related to the Celsius temperature.
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Yes this is true gas is related to the celcuis temp
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What are transitional elements in chemistry?
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How long does it take electrons to get from the car battery to the starting motor? Assume the current is 137 A and the electrons
WARRIOR [948]

Answer:

t = 55.79 min

Explanation:

First, the problem is asking for calculate the time that it takes electrons from the battery to the motor.

The general formula to calculate time is:

<em>t = d/V (1)</em>

Where:

d: distance or length

V: speed

Now, we don't have data of speed, but we can know an expression of current density in function of the distance which is the following:

<em>J = n*q*V (2)</em>

Where:

q: charge of the particle (1.6x10^-19 C)

n: number of charge carriers per unit of volume

Current density (J) is actually current per Area so:

<em>J = I/A (3)</em>

Replacing (3) in (2) we have:

I/A = nqV

Solving for V:

<em>V = I/Anq (4)</em>

Finally, if we replace this expression in (1) we have:

<em>t = nqAd / I (5)</em>

Now, the value of n, it's not given but it can be calculated because we have mass density, molar mass and avogadro's number, so this value of "n" can be calculated using the following expression:

<em>n = D * Av / MM (6)</em>

Where:

D: mass density (kg/m³)

Av: avogadro number (6.02x10^23 atom/mol)

MM: molar mass (kg/mol)

Putting the data that we know to calculate n we have:

n = 8960 * 6.02x10^23 / 0.0635

n = 8.49x10^28 atom/m³

Now with the value of n, we can finally calculate the time:

<em>t = nqAd / I </em>

A is the area and it should be in m²: 44.6 mm² / 1x10^6 m = 4.46x10^-5 m²

d is the length in meter: 75.7 cm / 100 cm/m = 0.757 m

so replacing these data in (5):

t = 8.49x10^28 * 1.6x10^-19 * 4.46x10^-5 * 0.757 / 137

t = 3,347.63 s

But the answer is in minute so:

t = 3,347.63 / 60

<em>t = 55.79 min</em>

so the electrons takes 56 min aprox. to go from the car battery to the starting motor.

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What color are the stars on the diagram with the lowest surface temperatures?
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A liquid dissolved in a gas results in a solution that is _____.
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The correct answer is C


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