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Statics 401211
Eng. Iqbal Marie
Course Introduction
This course is at a level which gives students the background and mathematical tools to take subsequent specialty courses like:
Dynamics, Fluid Mechanics and Strength of Materials
Contact Information
Eng. Iqbal Marie
Department of Civil Engineering
Room 3005
Email: [email protected]
Course text
Text Book:
Engineering Mechanics: Statics, 13e, Hibbeler,, Prentice Hall.
* Available in the Book shop .
Course Grade Determination
Grading:
First Exam: 20%
Second Exam 20%
Quizzes (3) 10%
Final Exam: 50% ( To be announced)
Quiz will be after certain modules have been completed.
Course content- Topic coverage
• Introduction • Units of Measurement, • Force Vectors • Equilibrium of a Particle • Force System Resultant • Equilibrium of a Rigid Body • Structural Analysis • Internal Forces, • Friction, • Center of Gravity and Centroids, • Moments of Inertia.
What is Statics ? Branch of physical sciences concerned with the state
of rest or motion of bodies subjected to forces is called Mechanics.
Statics is used to calculate forces in systems that don’t move, or move at constant velocity.
Statics is actually the application of mathematics and basic physics (Newton’s laws) to study forces in materials, machines and structures.
Forces are of interest to engineers for two reasons:
– they cause materials to deform and break, and – they cause things to move.
1.2 Fundamental Concepts Force: Generally considered as a push or a pull exerted by one body on another. Interaction occurs when there is direct contact between the bodies. Force is characterized by magnitude, direction and point of application.
Particle: An object having mass but the size is neglected. Rigid Body: A combination of a large number of particles which remain in a fixed position relative to each other, both before and after the application of a force.
Newton’s Three Laws of Motion
First Law: A particle originally at rest, or moving in a straight line with constant velocity, will remain in this state provided the particle is not subjected to unbalanced forces.
Second Law: A particle acted upon by an unbalanced force F experiences an acceleration that has the same direction as the force and a magnitude that is directly proportional to the force.
If F is applied to a particle of mass m then: F = ma.
Third Law: The mutual forces of action and reaction between two particles are equal, opposite and collinear.
1.3 Units of Measurements
International System of Units (SI): Length = meters (m);
Time = seconds (s);
Mass = kilograms (kg).
Force = Newtons (N) is derived from F=m*a.
1 kilogram mass has a weight of 9.81 Newtons at the earth’s surface.
They suggest writing large
numbers in scientific notation, with
exponents that are multiples of 3.
35000 N, or 3.5 x 104 N, is
35 kN.
When a quantity has several units
that are multiplied together (such
as metres x seconds = m.s), Or
just write m s,
Giga X 109 G
Mega X 106
M
Kilo X 103
k
Meter m
milli X 10-3
mm
micro X 10-6
nanometer X 10-9
n
Newton N
Pascal
Pa N/m2
X 106Pa MPa
1.4 International System of Units
SIGNIFICANT FIGURES
A significant digit is any digit provided it is not used to specify location of decimal point. 3,075 and 78.03 each have four significant figures.
* As a general rule, work calculations with four significant figures and report answers to three significant figures.
Dimensional homogeneity - in an equation where you are adding terms, they must all have the same units.
Eg. 1-1 Convert 2km/h to m/s.
2km/h = 2km 1000m h = 2000 m = 0.556 m/s
h km 60x60 s 3600 s
1.6 PROCEDURE FOR PROBLEM ANALYSIS
1. Read problem carefully, determine what is wanted.
2. Draw neat sketch, to scale, and label all important
quantities.
3. Decide on approach, which equations to apply.
4. Solve for quantities wanted.
5. Check accuracy of solution.
6. Use high quality paper, size A4 for submitting your
homework and quizes.
THANK YOU