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
icon
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.
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
steps

Step by step

Solved in 5 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,