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NemiM [27]
3 years ago
8

What percent of a present amount of radioactive radium (226Ra) will remain after 1200 years? The half life of 226Ra is 1599 year

s.
Mathematics
1 answer:
sp2606 [1]3 years ago
8 0

Answer:

59.44%

Step-by-step explanation:

<em>M_{R} = \frac{M_{O} }{2^{n} }</em>

<em>n=\frac{t}{t\frac{1}{2} }</em>

<em>Where M_{R} = mass remaining</em>

<em>M_{O} =original mass.</em>

<em>t= time </em>

<em>t\frac{1}{2} =half life</em>

t\frac{1}{2} =1599,  t= 1200, M_{O} =226,  M_{R} =?

n=\frac{1200}{1599}

n= 0.750469

M_{R} = \frac{226}{2^{ 0.750469} }

M_{R} =134.3367amu

percentage of mass remaining = \frac{134.3367amu}{226amu} *100%

                                                   = 59.44%

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Answer:

0.3571

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3 years ago
Andre and scott share the driving on a trip. Scott drives 7 miles more than three times tge distance Andre drives. If the trip i
Alekssandra [29.7K]

Answer:

Step-by-step explanation:

What we know is that A + S = 111. That is, the miles Andre drove plus the miles Scott drove totalled 111 miles. What we also know is that Scott drove quite a bit more than Andre did. Scott drove 7 miles more that ( +7 ) 3 times the number of miles Andrea drove. That looks like this algebraically:

S = 3A + 7

Now we can sub in that value for S to the original equation:

If A + S = 111 and S = 3A + 7, then

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S = 85 miles.

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3 0
3 years ago
Read 2 more answers
Please see attached below. Please explain
mylen [45]

Answer:

8 years

Step-by-step explanation:

The formula for the computation of simple interest is ...

... I = Prt

where I is the interest amount, P is the principal amount, r is the rate, and t is the number of years.

Fill in the given numbers and solve for t.

... 5704 = 15500×0.046×t

... 5704/713 = t = 8 . . . . . . divide by the coefficient of t

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3 0
3 years ago
Zachary completes a hypothesis test and finds that he rejects the null hypothesis. Which statement gives a reason for rejecting
padilas [110]

Answer:

The z-statistic lies in the critical region

Step-by-step explanation:

When a hypothesis test is performed, the decision to reject or not reject the null hypothesis is made on basis of following observations:

  • If the z-statistic falls in the critical or rejection region, there is enough evidence to reject the Null Hypothesis
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In the given statement Zachary rejects the Null Hypothesis, this means the z-statistic she calculated must have been inside the critical or rejection region. Hence the correct answer would be:

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3 years ago
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Can somebody please help me
irinina [24]

Answer:

72 degrees.

Step-by-step explanation:

As it is a right angled triangle and if the smaller acute angle = x degrees then:

x + 4x + 90 = 180.

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x = 18 degrees.

The larger acute angle = 4x = 4*18

=  72 degrees.

3 0
4 years ago
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