The answer is 7.85
First, you divide the diameter by two to get the radius (2.5) and then you multiply by pi(3.14) to get 7.85
Answer:
Step-by-step explanation:
Half life is the time taken by a radioactive substance to reduce of half of its original size
If the half life of radium is 1600, this means that the original radioactive substance N0 have reduced to N0/2 after 1600 years
if we are given N0 = 1000grams
The amount of the substance that will remain after 1600 years will be N0/2 i.e 1000/2 = 500g
<em>Hence 500 grams of radium will be left after 600years</em>
We are going to need to know the formula for the lateral surface area and volume of a cylinder in order to find our answers. Below are the equations:


is the height
is the radius
Using these formulas, we can solve these problems.


3,100 mg is 3.1 grams as there a 1000 mg in a gram.
3(x+5)=7-x3x+15=7-x4x=-8x=-2