Answer:
<h2>D= 3.9 miles</h2>
Step-by-step explanation:
Given data
speed v= 13 miles per hour
time taken t= 20min to hour 0.3 hours
the distance D
We know that the relationship between speed, time, and distance
speed=distance/time
13=D/0.3
(the expression above describes the relationship between distance, speed, and time)
making D subject of formula we have
D= 0.3*13
D= 3.9 miles
hence the distance is 3.9miles
From the calculation, the growth rate is 0.88.
<h3>What is the growth rate?</h3>
To find the relative growth rate
P1 = Poe^rt
P2 = Poe^rt
Thus;
1920 = Poe^4r ------ (1)
1966080 =Poe^12r -------(2)
P2/P1 gives;
1966080/1920 = Poe^12r/Poe^4r
1024 = e^12r/e^4r
1024 =e^8r
1024 = (e^r)^8
2^10 = (e^r)^8
e^r = 2^1.25
e^r = 2.38
r = ln(2.38)
r = 0.88
The initial size of the culture is;
1920 = Poe^(0.88 * 4)
Po = 1920/e^(0.88 * 4)
Po = 57
The expression for the exact number of bacteria after t hours is
P(t) = 57e^0.08t
The growth (in bacteria per hour) after 9.5 hours is
P(t) = 57e^(0.88 * 9.5)
P(t) = 243544
For the number to reach 72,000;
72,000 = 57e^0.88t
72,000/57 = e^0.88t
ln 126 = ln[e^0.88t]
4.8 = 0.88t
t = 4.8/0.88
t = 5.5 hours
Learn more about exponential growth;brainly.com/question/13674608
#SPJ1
Answer:
I'm am pretty sure that the answer is 320. Hope this helps!
Answer:
x = 3π/4, 5π/4
Step-by-step explanation:
cos(x+2π) = -√2/2, [0,2π]
cos(x)cos(2π)-sin(x)sin(2π) = -√2/2
cos(x) = -√2/2
x = 3π/4, 5π/4
Remember that the cosine function is periodic, so cos(θ+2π)=cos(θ).
