Answer:
The third choice, (160/3)π cm³
Step-by-step explanation:
The formula for volume of a cone is
V = (1/3)πr²h where r is the radius of the base, and h is the height
Here, r = 4 and h = 10. plug those values in and simplify...
V = (1/3)π(4²)(10)
V = (1/3)π(16)(10)
V = (1/3)π(160)
V = (160π)/3
Answer:
the question is incomplete, so I looked for a similar one:
<em>After the release of radioactive material into the atmosphere from a nuclear power plant, the hay was contaminated by iodine 131 ( half-life, 8 days). If it is all right to feed the hay to cows when 10% of the iodine 131 remains, how long did the farmers need to wait to use this hay? </em>
iodine's half life (we are given x, we need to find b):
0.5A₀ = A₀eᵇˣ
x = 8 days
we eliminate A₀ from both sides
0.5 = eᵇ⁸
ln 0.5 = ln eᵇ⁸
-0.69315 = b8
b = -0.69315 / 8 = -0.08664
since the farmers need to wait until only 10% of the iodine remains (we already calculated b, now we need to find x):
0.1A₀ = A₀eᵇˣ
0.1 = eᵇˣ
ln 0.1 = bx
where b = -0.08664
x = ln 0.1 / -0.08664 = -2.302585 / -0.08664 = 26.58 days
11 is your answer because 11* 11 is 121
-3.5 is your answer to this question