Answer:
D = L/k
Step-by-step explanation:
Since A represents the amount of litter present in grams per square meter as a function of time in years, the net rate of litter present is
dA/dt = in flow - out flow
Since litter falls at a constant rate of L grams per square meter per year, in flow = L
Since litter decays at a constant proportional rate of k per year, the total amount of litter decay per square meter per year is A × k = Ak = out flow
So,
dA/dt = in flow - out flow
dA/dt = L - Ak
Separating the variables, we have
dA/(L - Ak) = dt
Integrating, we have
∫-kdA/-k(L - Ak) = ∫dt
1/k∫-kdA/(L - Ak) = ∫dt
1/k㏑(L - Ak) = t + C
㏑(L - Ak) = kt + kC
㏑(L - Ak) = kt + C' (C' = kC)
taking exponents of both sides, we have

When t = 0, A(0) = 0 (since the forest floor is initially clear)


So, D = R - A =

when t = 0(at initial time), the initial value of D =

Answer:
20.57 cm
Step-by-step explanation:
Circumference of half circle = diameter + half of circumference

Answer:
12566.4 mm²
Step-by-step explanation:
The Petri dish shown has no lid. What is the surface area of the outside of the Petri dish? Round to the nearest tenth. A cylindrical-shaped Petri dish with a radius of 50 millimeters and a height of 15 millimeters.
TSA = Total Surface Area
CSA = Curved Surface Area
TSA of open cylinder = CSA of cylinder + area of base or top
= 2πrh + πr²
= πr(2h + r)
From the above question:
r = 50mm
h = 15mm
Hence,
= π × 50 (2 × 15 + 50)
= π × 50 (30 + 50)
= π × 50(80)
= π × 4000
= 12566.370614mm²
Approximately = 12566.4 mm²
The Surface Area of the petri dish with no lid = 12566.4 mm²
Answer:
85%
Step-by-step explanation:
There are two ways to solve this.
1. You can find the percent of birds, and then subtract that from 100%.
To find the percent of birds, divide 45/300 or make the denominator 100 by dividing both parts by 3.
45/300 (as a fraction)
=15/100
That is the same as 15%.
Subtract that from 100% and you get 85%.
2. You find the number of non-bird animals and make that a percent.
300-45=255 non-bird animals
255/300 (as a fraction)
=85/100
That is the same as 85%.
So either way, the answer is 85%.
D=√(6-0)²+(2-10)²
d=√(6)²+(-8)²
d=√36+64
d=√100
d=10