Section
2.3
Modeling
with
First
Order:
Problem
5
(1
point)
A
tank
contains
80
kg
of
salt
and
1000
L
of
water.
Pure
water
enters
a
tank
at
the
rate
8
L/min.
The
solution
is
mixed
and
drains
from
the
tank
at
the
rate
4
L/min.
(@)
Write
an
initial
value
problem
for
the
amount
of
salt,
y,
in
kilograms,
at
time
¢
in
minutes:
d.
4
q
d}t)_
—m
(kg/min)
y(0)
=
|
80
|
kg.
(b)
Solve
the
initial
value
problem
in
part
(a)
20000
YO
=|
55017
|
k9
(c)
Find
the
amount
of
salt
in
the
tank
after
4
hours.
amount
=
|
40.816
|
(kg)
(d)
Find
the
concentration
of
salt
in
the
solution
in
the
tank
as
time
approaches
infinity.
(Assume
your
tank
is
large
enough
to
hold
all
the
solution.)
concentration
=
@
(kg/L)
