<span>Assuming the reaction is of 1st order, we can
start using the formula for rate of 1st order reaction:</span>
dN / dt = k * N
Rearranging,
dN / N = k dt
Where N = amount of sample, k = rate constant, t = time
Integrating the equation from N = Ni to Nf and t = ti to
tf will result in:
ln (Nf / Ni) = k (tf – ti)
Since k is constant, we can equate to situations.
Situation 1 is triple in size every days, situation 2 is after 20 days.
ln (Nf / Ni) / (tf – ti) = k
ln (3Ni / Ni) / 4 = ln (Nf / 40) / 20
Calculating for Nf,
<span>Nf =
9,720 bacteria </span>
Answer:
B
Step-by-step explanation:
The equation of a parabola in vertex form is
y = a(x - h)² + k
where (h, k) are the coordinates of the vertex and a is a multiplier
Here the vertex = (- 2, - 3 ) , then
y = a(x - (- 2))² - 3 , that is
y = a(x + 2)² - 3
To find a, substitute any point on the graph into the equation
Using the coordinates of the y- intercept (0, 5 )
5 = a(0 + 2)² - 3 ( add 3 to both sides )
8 = a(2)² = 4a ( divide both sides by 4 )
2 = a
y = 2(x + 2)² - 3 → B
Answer:
B
Step-by-step explanation:
54.54 / 100 = .5454
(To get from Percent to Decimal, divide 100. To get from Decimal to Percent multiply 100)
Yess 5 is the correct answer