Answer:
The mass of the radioactive sample after 40 minutes is 12.8 g.
Step-by-step explanation:
The mass of the sample can be found by using the exponential decay equation:
Where:
N(t): is the amount of the sample at time t =?
N₀: is the initial quantity of the sample = 120 g
t = 40 min
λ: is the decay constant = 0.056 min⁻¹
Hence, the mass of the sample after 40 min is:
Therefore, the mass of the radioactive sample after 40 minutes is 12.8 g.
I hope it helps you!
<span>Lets find the volume of a cylinder with a diameter D=10 inches and lenght L= 20 inches. First we need to notice that the diameter is twice the size of the radius: D=2r. Then we write the equation for the volume of the cylinder. it is the base times the height: V=pi*r^2 * L. Now we input the nubmers in the equation: V=3.14*(D/2)^2 * L where r=D/2=5 inches and after calculating we get: V=1570 inches^3</span>
Answer:
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Answer:
y = -1/8 x² + 5
Step-by-step explanation:
Parabola opens vertically and vertex (h,k) = (0,5), pass point (4,3)
basic formula: y = a(x - h)² + k
y = a (x-0)² + 5
y = ax² + 5 pass (4,3)
3 = 16a + 5
a = (3-5)/16 = -1/8
equation: y = -1/8 x² + 5
check: pass another point (-4,3)
-1/8 * (-4)² + 5 = -2 + 5 = 3
4 times x minus 8 is the answer
