(a) Assuming that Q satisfies the differential equation Q' = -rQ, determine the decay constant r for carbon-14. (b) Find an expression for Q(t) at any time t, if Q(0) = Qo. (c) Suppose that certain remains are discovered in which the current residual amount of carbon-14 is 20% of the original amount. Determine the age of these remains.
Answer:
a) r = (In 2)/(t1/2) = (In 2)/5730 = 0.000121/year
b) Q(t) = Q₀ (e^-rt)
c) Are of the 20% remnant of Carbon-14 = 13301.14 years.
Step-by-step explanation:
Q' = -rQ
Q' = dQ/dt
dQ/dt = -rQ
dQ/Q = -rdt
Integrating the left hand side from Q₀ to Q₀/2 and the right hand side from 0 to t1/2 (half life, t1/2 = 5730 years)
In ((Q₀/2)/Q₀) = -r(t1/2)
In (1/2) = -r(t1/2)
In 2 = r(t1/2)
r = (In 2)/(t1/2) = (In 2)/5730 = 0.000121 /year
b) Q' = -rQ
Q' = dQ/dt
dQ/dt = -rQ
dQ/Q = -rdt
Integrating the left hand side from Q₀ to Q(t) and the right hand side from 0 to t.
In (Q(t)/Q₀) = -rt
Q(t)/Q₀ = e^(-rt)
Q(t) = Q₀ (e^-rt)
c) Q(t) = Q₀ (e^-rt)
Q(t) = 0.2Q₀, t = ? and r = 0.000121/year
0.2Q₀ = Q₀ (e^-rt)
0.2 = e^-rt
In 0.2 = -rt
-1.6094 = - 0.000121 × t
t = 1.6094/0.000121 = 13301.14 years.
Hope this Helps!
<u>Given</u>:
Given that the side length of the base of the square pyramid is 16 inches.
The height of the pyramid is 22.1 inches.
We need to determine the volume of the square pyramid.
<u>Volume of the square pyramid:</u>
The volume of the square pyramid can be determined using the formula,
where B is the area of the base and h is the height of the pyramid.
Substituting B = (16 × 16) and h = 22.1, we get;
Thus, the volume of the pyramid is 1885.9 cubic inches.
Answer:
Step-by-step explanation:
you multiply 2.56 by 3 and add 3.95 an equation would look like y=(3×2.56)+3.95
You have to combine like numbers
y-4x-1(1-6x)+3y+x
4y -4x-(1-6x)+x
4y - 4x - 1 + 6x + x
4y + 3x - 1
