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2 years ago

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Leila drove to the mountains last weekend. There was heavy traffic on the way there, and the trip took 10 hours. When Leila drov

e home, there was no traffic and the trip only took 7 hours. If her average rate was 18 miles per hour faster on the trip home, how far away does Leila live from the mountains?

1 answer:

9966 [12]2 years ago

5 0

Answer:

420 miles

Explanation:

Since distance is speed times time taken, you get two conditions:

$\left \{ {{d=v*10} \atop {d=(v+18)*7}} \right.$

Easiest way to solve it is to set the two condition equal - she's coming and going from the same place after all - and you get $10v=(v+18)*7\\10v=7v+3*6*7\\3v=3*6*7 \\v=42$ Replace in either equation and you'll get $d=420$

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Answer:

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Explanation:

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Length of the wrench, l = 0.5 m

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3 years ago

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3 years ago

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Potassium is a crucial element for the healthy operation of the human

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Answer:

1

The mass of the Potassium-40 is $m_{40}} = 2.88*10^{-6} kg$

2

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Explanation:

From the question we are told that

The isotopes of potassium in the body are Potassium-39, Potassium-40, and Potassium- 41

Their abundance is 93.26%, 0.012% and 6.728%

The mass of potassium contained in human body is $m = 3.0 g = \frac{3}{1000} = 0.0003 \ kg$ per kg of the body

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Now the mass of potassium in this body is mathematically evaluated as

$m_p = m * m_1$

substituting value

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$Dose = \frac{E}{m_1}$

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$Dose_s = 26.4 *10^{-10}$

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