Answer:
a) -900 L/min
b) 63000 L
c) v = -900t +63000
d) 7200 L
Step-by-step explanation:
a) You are given two points on the curve of volume vs. time:
(t, v) = (20, 45000) and (70, 0)
The rate of change is ...
Δv/Δt = (0 -45000)/(70 -20) = -45000/50 = -900 . . . . liters per minute
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b) In the first 20 minutes, the change in volume was ...
(20 min)(-900 L/min) = -18000 L
So, the initial volume was ...
initial volume -18000 = 45000
initial volume = 63,000 . . . . liters
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c) Since we have the slope and the intercept, we can write the equation in slope-intercept form:
v = -900t +63000
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d) Put the number in the equation and do the arithmetic.
When t=62, the amount remaining is ...
v = -900(62) +63000 = -55800 +63000 = 7200
7200 L remain after 62 minutes.
