MECH 234 & 235 Engineering Mechanics: STATICS

Prof. G. Milano, PE n 239-Colton Hall n n n Office Hours 4:00 - 5:00 M,W

It’s on the web: n Course Outline n General Information n Examples n Homework Solutions n 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 n length = magnitude n angle = orientation n arrowhead = direction

Forces are Vectors n rectangular coordinates n polar coordinates

Rectangular Coordinates F = 4i + 3j 4 units horizontal 3 units vertical Length = Magnitude

Rectangular Coordinates F = 4i + 3j 4 units horizontal 3 units vertical Hypotenuse =  4² + 3² = 5

Polar Coordinates F = 5  36° Horizontal axis Vertical axis  = 36° Length = 5 units

Polar Coordinates F = 5  36° X component = 5 cos 36° Y comp. = 5 sin 36°  = 36° Length = 5 units

Force Vector n F = 5  36° n F = 5 cos 36° i + 5 sin 36° j n F = 4i + 3j n 5 = length = magnitude n 36° = angle = orientation

Force Vectors n graphical solutions n add vectors head to tail n analytical solutions n 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 Some files are.pdf and you’ll need the Adobe Acrobat Reader. Download it FREE.