1. MECH 234 & 235 Engineering Mechanics: STATICS

2. Prof. G. Milano, PE n 239-Colton Hall n 973-596-5930 n milano@njit.edu n Office Hours 4:00 - 5:00 M,W

3. It’s on the web: n Course Outline n General Information n Examples n Homework Solutions n Tutoring Schedule

4. STATICS The study of force systems in equilibrium; i.e., balanced force systems.

5. STATICS  F = 0 (forces) all forces add up to zero  the system is balanced

6. STATICS  M = 0 (moments) moments add up to zero  the system is balanced

7. DYNAMICS  F = ma forces do not equal zero  the system is unbalanced

8. DYNAMICS  T = J  moments do not equal zero  the system is unbalanced

9. Forces are Vectors n length = magnitude n angle = orientation n arrowhead = direction

10. Forces are Vectors n rectangular coordinates n polar coordinates

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

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

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

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

15. 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

16. Force Vectors n graphical solutions n add vectors head to tail n analytical solutions n add like components

17. Let’s get to work... Let’s look at some examples from the book and on the web.

18. Let’s go to the web...... Some files are.pdf and you’ll need the Adobe Acrobat Reader. Download it FREE.