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Kay [80]
3 years ago
8

A rock formed with 1,000 atoms of a radioactive parent element, but only contains 250 radioactive parent atoms today. If the hal

f-life is 1,000,000 years, how old is the rock?
Physics
1 answer:
alisha [4.7K]3 years ago
8 0

Answer:

age of rock is 2 million years

Explanation:

M_{R}=\frac{M_{O} }{2^{n} }

Where M_{R} is mass remaining

            M_{R} is original mass

         n= t/t(1/2) , which is the ratio of time to half life

M_{O} = 1000atoms

M_{R} =250 atoms

250 =\frac{1000}{2^{n} }

2^{n} = \frac{1000}{250}\\  2^{n} =4\\2^{n}  = 2^{2}\\ n=2

n =\frac{t}{t\frac{1}{2} }

t =t(1/2) *n

t(1/2) =1000000 years

t=1000000 *2

t=2,000,000 years

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Answer:

16 Newtons

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3 years ago
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steposvetlana [31]

Answer:

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Explanation:

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The cheetah is the fastest land animal, reaching speeds as high as 33 m/s, or roughly 75 mph. What is the kinetic energy of a 65
pochemuha

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