MANUALTO
ACCOMPANYORBI
TAL MECHANICS
FOR
ENGINEERING
STUDENTS
,SOLUTIONS MANUALTO ACCOMPANYORBITAL MECHANICS FOR
ENGINEERING STUDENTS
Problem 1.1
(A)
A A Ax Iˆ Ay ˆj Azkˆ Ax Iˆ Ay ˆj Azkˆ
Ax Iˆ Ax Iˆ Ay ˆj Azkˆ Ay ˆj Ax Iˆ Ay ˆj Azkˆ Azk ˆ Ax Iˆ Ay ˆj Azkˆ
Ax2 Iˆ Iˆ Ax Ay Iˆ ˆ j Ax Az Iˆ Kˆ Ay Ax ˆ j Iˆ Ay2 ˆ j ˆ j Ay Az ˆ j Kˆ
AzAx Kˆ Iˆ AzAy Kˆ ˆj Az2 Kˆ Kˆ
Ax 2 1 Ax Ay 0 Ax Az 0 Ay Ax 0 Ay 2 1 Ay Az 0 Az Ax 0 Az Ay 0 Az2 1
Ax 2 Ay 2 Az2
But, According To The Pythagorean Theorem, Ax 2 A
y
2
A
z
2
A2 , Where A A , The Magnitude Of
The Vector A . Thus A A A2 .
(B)
Iˆ ˆj Kˆ
A B C A Bx By Bz
Cx Cy Cz
Ax Iˆ Ay ˆj Azkˆ Iˆ Bycz Bzcy ˆj Bxcz Bzcx Kˆ Bxcy Bycx
Ax By cz Bzcy Ay Bx cz Bzcx Az Bx cy By cx
Or
A B C Ax by cz Ay bzcx Azbx cy Ax bzcy Ay bx cz Azby cx (1)
Note That A B C C A B , And According To (1)
C A B Cx ay bz Cy Azbx Cz Ax by Cx azby Cy Ax bz Cz Ay bx (2)
The Right Hand Sides Of (1) And (2) Are Identical. Hence A B C A B C .
(C)
Iˆ ˆj Iˆ ˆj Kˆ
Kˆ
A B C Ax Iˆ Ay ˆj Azkˆ Bx By Bz Ax Ay Az
Cx CyBy cz Bzcy
Cz Bzcx Bx cy Bx cy By cx
Ay Bx cy By cx Az Bzcx Bx cz Iˆ Az By cz Bzcy Ax Bx cy By cx ˆj
A B c B c A B c B c Kˆ
x z x x z y y z
z y
Ay bx cy Azbx cz Ay by cx Azbzcx Iˆ Ax by cx Azby cz Ax bx cy Azbzcy ˆj
x z x y z y x x z y y z
A b c A b c A b c A b c Kˆ
Bx Ay cy Azcz Cx Ay by Azbz Iˆ By Ax cx Azcz Cy Ax bx Azbz ˆj
z x x y y Cz Axb x Ayby K
B A c A c ˆ
Add And Subtract The Underlined Terms To Get
, SOLUTIONS MANUALTO ACCOMPANYORBITAL MECHANICS FOR
ENGINEERING STUDENTS
A B C Bx Ayc y Azc z Axcx Cx Ayby Azb z Axbx Iˆ
By Ax cx Azcz Ay cy Cy Ax bx Azbz Ay by ˆj
z x x
B A c A c A c
yy zz C z A b
x x
A b
y y A b
z z Kˆ
Bx Iˆ By ˆ j Bzkˆ Axcx Aycy Azcz Cx Iˆ Cy ˆj Czkˆ Axbx Ayby Azbz
Or
A B C B A C CA B
Problem 1.2 Using The Interchange Of Dot And Cross We Get
A B C D A B C D
But
A B C D C A B D (1)
Using The Bac – Cab Rule On The Right, Yields
A B C D AC B BC A D
Or
A B C D A DC B B DC A (2)
Substituting (2) Into (1) We Get
A B C D A CB D A DB C
Problem 1.3
Velocity Analysis
From Equation 1.38,
V Vo Rrel Vrel . (1)
From The Given Information We Have
Vo 10Iˆ 30Jˆ 5 0 K̂ (2)
Rrel R Ro 150Iˆ 200Jˆ 3 0 0 K̂ 300Iˆ
200Jˆ 1 0 0 K̂ 150Iˆ 400Jˆ (3)
2 0 0 K̂
Iˆ Jˆ K̂
Rrel 0.6 0.4 1.0 320Iˆ 270Jˆ 3 0 0K̂ (4)
150 400 200