MECH 234 & 235
Engineering Mechanics:
STATICS
Prof. G. Milano, PE
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239-Colton Hall
973-596-5930
milano@njit.edu
Office Hours
4:00 - 5:00 M,W
It’s on the web:
 Course
Outline
 General Information
 Examples
 Homework Solutions
 Tutoring Schedule
STATICS
The study of force systems
in equilibrium;
i.e., balanced force systems.
STATICS
F = 0
(forces)
all forces add up to zero
 the system is balanced
STATICS
M = 0
(moments)
moments add up to zero
 the system is balanced
DYNAMICS
 F = ma
forces do not equal zero
 the system is unbalanced
DYNAMICS
 T = J
moments do not equal zero
 the system is unbalanced
Forces are Vectors
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length = magnitude
angle = orientation
arrowhead = direction
Forces are Vectors
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rectangular coordinates
polar coordinates
3 units vertical
Rectangular Coordinates
F = 4i + 3j
4 units horizontal
3 units vertical
Rectangular Coordinates
F = 4i + 3j
4 units horizontal
Vertical axis
Polar Coordinates
F = 5  36°
 = 36°
Horizontal axis
Y comp. = 5 sin 36°
Polar Coordinates
F = 5  36°
 = 36°
X component = 5 cos 36°
Force Vector
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F = 5  36°
F = 5 cos 36° i + 5 sin 36° j
F =
4i + 3j
5 = length = magnitude
36° = angle = orientation
Force Vectors
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graphical solutions
add vectors head to tail
analytical solutions
add like components
Let’s get to work ...
Let’s look at some examples
from the book and on the web.
Let’s go to the web...
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the Adobe
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