Answer:
Step-by-step explanation:
The surface area of a square pyramid is the sum of the area of the squared base + 4 times the area of each triangular face, therefore:
where:
is the area of the base, where
L is the length of the base
is the area of each triangular face, where
h is the height of the face
Substituting,
For the model in this problem,
L = 12
h = 8
Therefore, the surface area here is:
First one is 14
Second one is 45
Third one is 43
Fourth one is 40
This is a typical radioactive decay problem which uses the general form:
A = A0e^(-kt)
So, in the given equation, A0 = 192 and k = 0.015. We are to find the amount of substance left after t = 55 years. That would be represented by A. The solution is as follows:
A = 192e^(-0.015*55)
<em>A = 84 mg</em>
Answer:
<u><em>Explanation:</em></u>
Since the distance from the school to the bank is 4 units, then the library would be 4 units always from the school!
<em><u>How to solve:</u></em> Look at the answer choices and see which one is 4 units away.
<em><u>Answer:</u></em> B, (2,8)
