On a dark night, two ships, Saga and Hero, sail parallel to a straight coastline on which there are two lights of equal brightness, 16 kilometres apart. P(x, b) b (-8, 0) (8, 0) x
On a dark night, two ships, Saga and Hero, sail parallel to a straight coastline on which there are two lights of equal brightness, 16 kilometres apart. P(x, b) b (-8, 0) (8, 0) x
Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
Related questions
Question
![On a dark night, two ships, Saga and Hero, sail parallel to a straight coastline on
which there are two lights of equal brightness, 16 kilometres apart.
P(x, b)
(-8, 0)
(8, 0) x
Suppose the coastline is represented by the x axis where the origin O is chosen
to be the midpoint of the light sources. It is known that the (total) brightness
from the lights on a ship at point P(x, b) is
1
I =
b² +(x+8)² 'b² +(x-8)²
+
dI
(i) Show that
dx
2P
where
P= (x+8)(3² +(x – 8)*)* +(x -8)(s² +(x + 8)*)* |
and Q = (3° +(x +8)*)} (s? +(x-87)'.
To answer parts (ii) and (iii), you may assume the following factorisation, given
by a computer package, that
P= 2x(x² + 64 + b? +16/64 + b² (x² + 64 + b² –16/64 + b²).
(ii) Saga sails parallel to the coast at a distance 15 km from the coast.
dI
show that, as Saga sails from left to right, the brightness
By considering
on Saga increases to a maximum when x= 0 and then decreases.
dx
(iii) Hero sails parallel to the coast at a distance 6 km from the coast.
Describe how the brightness on Hero changes as Hero sails from left to
right. Give clear reasons for your answer.](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2Feefb1a2d-d005-4a1b-a1be-7dc6fa563424%2Ffcc9bd85-d712-41b0-9a84-b26a0e8e8f08%2Fc6p7nk_processed.jpeg&w=3840&q=75)
Transcribed Image Text:On a dark night, two ships, Saga and Hero, sail parallel to a straight coastline on
which there are two lights of equal brightness, 16 kilometres apart.
P(x, b)
(-8, 0)
(8, 0) x
Suppose the coastline is represented by the x axis where the origin O is chosen
to be the midpoint of the light sources. It is known that the (total) brightness
from the lights on a ship at point P(x, b) is
1
I =
b² +(x+8)² 'b² +(x-8)²
+
dI
(i) Show that
dx
2P
where
P= (x+8)(3² +(x – 8)*)* +(x -8)(s² +(x + 8)*)* |
and Q = (3° +(x +8)*)} (s? +(x-87)'.
To answer parts (ii) and (iii), you may assume the following factorisation, given
by a computer package, that
P= 2x(x² + 64 + b? +16/64 + b² (x² + 64 + b² –16/64 + b²).
(ii) Saga sails parallel to the coast at a distance 15 km from the coast.
dI
show that, as Saga sails from left to right, the brightness
By considering
on Saga increases to a maximum when x= 0 and then decreases.
dx
(iii) Hero sails parallel to the coast at a distance 6 km from the coast.
Describe how the brightness on Hero changes as Hero sails from left to
right. Give clear reasons for your answer.
Expert Solution
![](/static/compass_v2/shared-icons/check-mark.png)
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by step
Solved in 5 steps with 1 images
![Blurred answer](/static/compass_v2/solution-images/blurred-answer.jpg)
Recommended textbooks for you
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
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…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
![Advanced Engineering Mathematics](https://www.bartleby.com/isbn_cover_images/9780470458365/9780470458365_smallCoverImage.gif)
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
![Numerical Methods for Engineers](https://www.bartleby.com/isbn_cover_images/9780073397924/9780073397924_smallCoverImage.gif)
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…](https://www.bartleby.com/isbn_cover_images/9781118141809/9781118141809_smallCoverImage.gif)
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
![Mathematics For Machine Technology](https://www.bartleby.com/isbn_cover_images/9781337798310/9781337798310_smallCoverImage.jpg)
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
![Basic Technical Mathematics](https://www.bartleby.com/isbn_cover_images/9780134437705/9780134437705_smallCoverImage.gif)
![Topology](https://www.bartleby.com/isbn_cover_images/9780134689517/9780134689517_smallCoverImage.gif)