Answer:
6.2 g
Explanation:
In a first-order decay, the formula for the amount remaining after <em>n</em> half-lives is
where
<em>N</em>₀ and <em>N</em> are the initial and final amounts of the substance
1. Calculate the <em>number of half-lives</em>.
If
2. Calculate the <em>final mass</em> of the substance.
It’s C I think and I’m not sure
Answer:

Explanation:
Volume of a cone:
We have
and we want to find
when the height is 2 cm.
We can see in our equation for the volume of a cone that we have three variables: V, r, and h.
Since we only have dV/dt and dh/dt, we can rewrite the equation in terms of h only.
We are given that the height of the cone is 1/5 the radius at any given time, 1/5r, so we can write this as r = 5h.
Plug this value for r into the volume formula:
Differentiate this equation with respect to time t.
Plug known values into the equation and solve for dh/dt.
Divide both sides by 100π to solve for dh/dt.
The height of the cone is increasing at a rate of 1/10π cm per second.