Answer:
c) The planetoid is being attracted toward another massive object.
Explanation:
We can rule out a, the planetoid is travelling through space, friction is effectively nonexistent. B can be ruled out as well, as there is nothing in space that could naturally repel a planetoid. D is also implausible, as the question says the planetoid slows down for a certain period in its orbit, suggesting this behavior is repeated. Option c is incredibly likely, as the planetoid is far from the sun, a large mass, possibly far smaller than the sun but also far closer to the planetoid, could have the effect described in the question.
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!!!
Characters, A backround story
Answer:
where is the figure?
Explanation:
I'll try. OK? don't blame me if I'm wrong T_T
13×9=117
8×9=54
11(I think there is an unknown line)
