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d1i1m1o1n [39]
3 years ago
15

IS ANYONE GOOD AT CALCULUS? PLEASE HELP!!! The rate at which a certain radioactive isotope decays is given by = negative 0.0032

y, where y is the amount of the isotope after t days. After approximately how many days would the amount of this isotope in a sample reach 75% of its original amount?

Mathematics
1 answer:
victus00 [196]3 years ago
6 0

Answer:

90 days.

Step-by-step explanation:

dy/dt = - 0.0032y

dy = -0.0032y dt

dy/y = -0.0032 dt

Integrating:

ln y = -0.0032t + c     where c is some constant

y = e^(-0032t) + e^c

y = A e^(-0032t)   where A is a constant.

At time 0 we can let y = 1 so in that case A = 1

When there is 0.75 of y left:

0.75 = e^-0032t

ln 0,75 =  -0032 t

t = ln 0.75 / -0032

t = 90.

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Answer:

See explanation below

Step-by-step explanation:

Since each time after the person gets off the scale, the reading is 2 lb the person's weight must be near the mean of

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We could estimate the uncertainty as <em>the standard error SE </em>

\bf SE=\frac{s}{\sqrt{n}}  

where  

<em>s = standard deviation of the sample </em>

<em>n = 4 sample size. </em>

Computing s:

\bf s=\sqrt{\frac{(146-148.25)^2+(149-148.25)^2+(148-148.25)^2+(150-148.25)^2}{4}}=1.479

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<em>It is not possible to estimate the bias, since it is the difference between the true weight and the mean, but we do not know the true weight. </em>

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3 years ago
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grandymaker [24]
5/12lb of dog food in each container.

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6 0
3 years ago
What is the following product?
VMariaS [17]

For this case we must find the product of the following expression:

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\sqrt {12 * 18} =\\\sqrt {216} =

We rewrite the 216 as6 * 6 * 6 = 6 ^ 3 = 6 ^ 2 * 6

\sqrt {6 ^ 2 * 6} =

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6 0
3 years ago
Read 2 more answers
A triangle has side lengths of 15 10 and 7 is it a right triangle
lions [1.4K]

Answer:

No, it is not a right triangle.

Step-by-step explanation:

Given:

The sides of the triangle =  15 10 and 7

To Find:

Whether the triangle is a right triangle = ?

Solution:

According to Pythagorean theorem , In an right triangle the the sum of the squares of the two smaller sides must equal to the square of the larger side

a^2 +b^2 =c^2\\

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7 0
3 years ago
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Reika [66]
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