7. An element decomposes at a rate proportional to its amount at any instant. In 100 years, 100 mg of the amount of element decomposes to 96 mg. In 100 years, determine the amount left. a. 88.60 O b. 92.16 O c. 95.32 O d. 90.72

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question
7.
An element decomposes at a rate
Which of the following equations is a
variable separable DE?
proportional to its amount at any instant. In
100 years, 100 mg of the amount of element
decomposes to 96 mg. In 100 years,
determine the amount left.
O a. 2y dx = (x² + 1) dy
88.60
O b. (x+ x? y) dy = (2x + xy?) dx
о с. у? dx + (2х - зу) dy - 0
O b. 92.16
Oc. 95.32
o d. (x+ y) dx – 2y dy = 0
o d. 90.72
8.
10.
The solution of the differential equation
(x* +1) +(x² +1) = 0
The solution of differential equation
dr
dy
dr
! + tan
1-x
y=.
1+x
Oa.
Ob.
y=2+x
O a. cos(y/x)=xc
Oc.
1+x
y=:
1-x
O b. sec?(y/x)=xc
od.
y=x(x-1)
Oc. sin(y/x)=xc
O d. cot(y/x)=xC
Transcribed Image Text:7. An element decomposes at a rate Which of the following equations is a variable separable DE? proportional to its amount at any instant. In 100 years, 100 mg of the amount of element decomposes to 96 mg. In 100 years, determine the amount left. O a. 2y dx = (x² + 1) dy 88.60 O b. (x+ x? y) dy = (2x + xy?) dx о с. у? dx + (2х - зу) dy - 0 O b. 92.16 Oc. 95.32 o d. (x+ y) dx – 2y dy = 0 o d. 90.72 8. 10. The solution of the differential equation (x* +1) +(x² +1) = 0 The solution of differential equation dr dy dr ! + tan 1-x y=. 1+x Oa. Ob. y=2+x O a. cos(y/x)=xc Oc. 1+x y=: 1-x O b. sec?(y/x)=xc od. y=x(x-1) Oc. sin(y/x)=xc O d. cot(y/x)=xC
1.
3.
5.
A tank contains 80 gals. of pure water. A
A container has 100 liters of brine containing
50 kg. total of dissolved salt. Pure water is
An organic compound decomposes at a rate
proportional to the amount present. If the
half of the original amount disappears after
1000 years, what is the percentage lost in
100 years?
brine solution with 2 lbs/gal of salt enters at
allowed to run into the container at the rate
of 3 L/min. Brine runs out of the tank at the
2 gals/min, and the well-stirred mixture
rate of 2 L/min. The instantaneous
leaves at the same rate. Find (a) the amount
concentration in the tank is kept uniform by
of salt in the tank at any time
stirring. How much salt is in the tank at the
end of one hour?
O a. 4.30%
a. 80 lbs
a. 15.45 kg
Ob. 19.53 kg
O. 12.62 kg
od. 20.62 kg
O b. 4.50%
O b. 41.3 Ibs
Oc. 5.35%
Oc. 23 Ibs
O d. 6.70%
o d. 27.73 Ibs
2.
6.
Determine the solution of the differential
An island has population that doubles in 50
equation dy
dr
+y cot x = coSX
years. Determine how long will the
population be five times as much? Assume
Newton's law of cooling states that, the rate
at which a substance change temperature in
air is directly proportional to the difference
that the rate of increase is proportional to the
sin'z +c
Oa.
O a.
ycos x =
between the temperatures of the substance
number inhabitants.
and that of air. If the temperature of the air is
30° and the substance cools from 100* to
Ob.
ob.
ycos x =
sin²z
70° in 15 minutes, how long will it take to
cool 100* to 50*?
O a. 100 years
O c. ysin x = cosz +c
b. 98 years
a. 33. 59 min
O b. 43.60 min
O. 35.39 min
o d.
ysin x =
sin²z
ос. 120 years
O d. 116 years
o d. 45.30 min
Transcribed Image Text:1. 3. 5. A tank contains 80 gals. of pure water. A A container has 100 liters of brine containing 50 kg. total of dissolved salt. Pure water is An organic compound decomposes at a rate proportional to the amount present. If the half of the original amount disappears after 1000 years, what is the percentage lost in 100 years? brine solution with 2 lbs/gal of salt enters at allowed to run into the container at the rate of 3 L/min. Brine runs out of the tank at the 2 gals/min, and the well-stirred mixture rate of 2 L/min. The instantaneous leaves at the same rate. Find (a) the amount concentration in the tank is kept uniform by of salt in the tank at any time stirring. How much salt is in the tank at the end of one hour? O a. 4.30% a. 80 lbs a. 15.45 kg Ob. 19.53 kg O. 12.62 kg od. 20.62 kg O b. 4.50% O b. 41.3 Ibs Oc. 5.35% Oc. 23 Ibs O d. 6.70% o d. 27.73 Ibs 2. 6. Determine the solution of the differential An island has population that doubles in 50 equation dy dr +y cot x = coSX years. Determine how long will the population be five times as much? Assume Newton's law of cooling states that, the rate at which a substance change temperature in air is directly proportional to the difference that the rate of increase is proportional to the sin'z +c Oa. O a. ycos x = between the temperatures of the substance number inhabitants. and that of air. If the temperature of the air is 30° and the substance cools from 100* to Ob. ob. ycos x = sin²z 70° in 15 minutes, how long will it take to cool 100* to 50*? O a. 100 years O c. ysin x = cosz +c b. 98 years a. 33. 59 min O b. 43.60 min O. 35.39 min o d. ysin x = sin²z ос. 120 years O d. 116 years o d. 45.30 min
Expert Solution
steps

Step by step

Solved in 2 steps with 1 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,