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Explore the principles of statics in engineering, including problem-solving strategies, software utilization, and mechanics reform. Learn Newton's laws, measurement basics, and the SI and U.S. customary units. Join us for a deep dive into rigid bodies, deformable bodies, and fluid mechanics.
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ME 221 StaticsFall 2003 Mr. Hinds 3523 EB hinds@msu.edu
Administrative Details • Syllabus will be posted on the web • www.angel.msu.edu (Angel) • Lecture attendance • Web will be used for announcements but not all important announcements given in class may be posted on the web • Bring books to class for example problems • Sample problems will be an integral part of lecture • Lecture behavior • Class size requires professional conduct Lecture 1
Administrative Details cont. • Exams • Dates set and given on syllabus • first test date set for 100% refund drop date • Format • closed book, closed notes, calculator • Excused absences: See syllabus • Philosophy • Most problems like HW; some problems conceptually same as HW but somewhat different Lecture 1
Administrative Details cont. • Homework & quizzes • solutions will be posted • all or partial problems will be graded • lecture quizzes used as “scrimmages” • quizzes in the last 15-20 minutes of lecture • similar to assigned homework • generally announced - some unannounced Lecture 1
Administrative Details cont. Questions?? Lecture 1
ENGINEERING… The Future and the Challenges…..?? Lecture 1
Problem Solving Strategy 1 - Modeling of physical problem (free body diagram) 2 - Expressing the governing physical laws in mathematical form 3 - Solving the governing equations 4 - Interpretation of the results Lecture 1
Mechanics Reform • Textbook offers a departure from past standards • recognizes the power of computer software in solving problems • MathCAD, MatLab, Maple, Mathmatica, VB, etc. • calculators may be effectively utilized as well • before using the software, the problem must be properly posed • posing the problem will be emphasized in this class Lecture 1
Mechanics Reform cont. • Software helps us with: • trigonometry • units conversion • Software does not help with: • envisioning the forces • systems of equations • iterative problems for design purposes • applying the proper laws of physics Lecture 1
Mechanics • Broadly defined as the study of bodies that are acted upon by forces. • Types of bodies • particles (considered rigid bodies) • rigid bodies - relative distance between any two points remains constant throughout motion • deformable bodies • fluids Lecture 1
Rigid Static Statics Static Deformable Mech Matl Dynamic Rigid Dynamics Dynamic Fluid Dyn Deformable Mechanics Overview Lecture 1
And now ... Statics Lecture 1
Chapter 1: Measurement • Newton’s Laws of Motion • Space and Events • Vectors and Scalars • SI Units (Metric) • U.S. Customary Units • Unit Conversion • Scientific Notation • Significant Figures Lecture 1
Basics: Newton’s Laws • Every body or particle continues in a state of rest or of • uniform motion in a straight line, unless it is compelled • to change that state by forces acting upon it. (Law of Inertia) • The change of motion of a body is proportional to the • net force imposed on the body and is in the direction of • the net force. F=ma • If one body exerts a force on a second body, then the • second body exerts a force on the first that is equal in • magnitude, opposite in direction, and collinear. Lecture 1
Law of Universal Gravitation: Any two particles are attracted to each other with a force whose magnitude is proportional to the products of their gravitational masses and inversely proportional to the square between them. F=Gm1m2/r2 where G = 66.73 x 10-12 m3/kg-s2 Lecture 1
y mi x z Basics • Space -- we need to know the position of particles • Event -- position at a given time Lecture 1
Basics cont. • vectors must have direction specified • e.g., velocity, force, acceleration • Two broad quantities • scalars have no direction associated with them • e.g., temperature, mass, speed, angle • Mass -- a scalar that characterizes a body’s resistance to motion • Force -- (vector) the action of one body on another through contact or acting at a distance Lecture 1
International System of Units:The SI system • Length meters m • Time seconds s • Mass kilogram kg • Force Newton N 1 kg m/s2 • See table 1-1 for prefixes Compound units Remember: Speed = distance/time so in SI units, speed is measured in m/s Lecture 1
U.S. Customary Units • Length foot ft • Time seconds s • Mass slug slug • Force pound lb slug ft/s2 • *Remember: W= mg • where g = 32.17 ft/s2 Lecture 1
Numerical Answers • equal 5: then all digits after it are dropped • Significant figures • Use 3 significant digits • If first digit is 1, then use next 3 • Rounding off the last significant digit • less than 5: all digits after it are dropped • greater than 5 or equal 5 followed by a nonzero digit: round up Lecture 1
END OF BASICS Lecture 1