Answer: "hydrologic cycle" .
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The United States is an example of Democracy.
One option that is not true about Polar projections is that C. It only shows one hemisphere.
<h3>What do polar projections do?</h3>
Polar projections are a type of azimuthal projection that aim to showcase the furthest areas north and south of the Earth. This means that they show both the Arctic and Antarctica in the model.
The Artic is in the Northern hemisphere and Antarctica is in the Southern hemisphere. This means that both hemispheres are shown and it is wrong to say that polar projections show only one hemisphere.
Find out more on polar projections at brainly.com/question/298112
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Answer:
The age of the rock = 2800.6 million years = 2.8 billion years.
A simple method of analysis similar to Carbon dating is used to obtain the required age of the rock. Radioactive substances decay according to first order reaction kinetics. So, plugging all the required parameters into the general equation for amount of substance left in a first order decay gives us the age of the rock.
Explanation:
Half life of Uranium-235 = 700 million years (from literature)
The decay of radioactive substances follow first order reaction kinetics.
The general equation is given as
A(t) = A₀ e⁻ᵏᵗ
A(t) = Amount of radioactive substance left after a particular time = 6.25%
A₀ = initial amount of radioactive substance = 100%
t = time that has passed since the beginning = age of the rock = ?
k = decay constant
The decay constant is related to the half life (T) through the relation,
k = (In 2)/T
k = (0.693/700) = 0.00099 /million years
A(t) = A₀ e⁻ᵏᵗ
6.25 = 100 e⁻ᵏᵗ
0.0625 = e⁻ᵏᵗ
In e⁻ᵏᵗ = In 0.0625 = -2.7726
-kt = - 2.7726
t = (2.7726/0.00099) = 2800.6 million years
t = 2.8 billion years.
Hope this Helps!!!
Two factors that helped Brazil’s economic growth is foreign investments, and exports
