Answer:
a) 
b) 334,858 bacteria
c) 4.67 hours
d) 2 hours
Step-by-step explanation:
a) Initial number of bacteria is the coefficient, that is, 250. And the growth rate is the coefficient besides “t”: 0.15. It’s rate of growth because of its positive sign; when it’s negative, it’s taken as rate of decay.
Another way to see that is the following:
Initial number of bacteria is N(0), which implies 
. And 
. The process is:
b) After 2 days means 
. So, we just replace and operate:
c) 
d) 
You started out with 260, and increased to 430.
The amount you increased was (430 - 260) = 170
170 is (170/260) = <em>65.4%</em> of what you started with.
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Another way:
The new amount is (430/260) of the old amount.
430 / 260 = 1.654 = 165.4%
The original amount was 260.
You started with 100% of it.
You ended up with 165.4% of it.
That's an increase of 65.4% .
Answer:
1.length = 15, width = 12, height = 13
2. 13 × 12 × 15 = 2340
Step-by-step explanation:
3 ÷ 1/4 = 12
3 3/4 = 15/4
15/4 ÷ 1/4 = 15
3 1/4 ÷ 1/4 = 13
length = 15
width = 12
height = 13
13 × 12 × 15 = 2340
We are given with the following given
dV/dt = 35 m3/min
h = (3/2)D
What is asked is
dr/dt at t = 7 min
The volume of a cone is
V = (1/3)πr²h
From the given
h = (3/2)D
since D = 2r
h = 3r
Subsituting
V = πr³
At t = 7 min, the volume is
V = 35(7)
V = 245
and the radius is
245 = πr³
r = 4.27
Differentiating the volume
dV/dt = 3πr² dr/dt
From the given
dV/dt = 35
Subsituting
35 = 3πr² dr/dt
So,
dr/dt = 0.20 m/s
and
dh/dt = 0.60 m/s
