What is statics? Lecture 1

Slides:



Advertisements
Similar presentations
CE Statics Lecture 1.
Advertisements

Introduction to Statics
Chapter 13: Kinetics of a Particle: Force and Acceleration.
Chapter 4 The Laws of Motion. Forces Usually think of a force as a push or pull Usually think of a force as a push or pull Vector quantity Vector quantity.
PREPARED BY…….. ANJALI ACHARYA ( ) SHIVANI GAJJAR ( ) MANALI PATEL ( )
Statics (ENGR 2214) Prof S. Nasseri What you need to know from Physics! ENGR 2214.
Forces and Newton’s Laws of Motion
Chapter 4 The Laws of Motion. Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting.
Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting on them Conditions when Classical.
Fundamental Concepts and Principles
MAE 242 Dynamics – Section I Dr. Kostas Sierros. Problem.
JJ205 ENGINEERING MECHANICS COURSE LEARNING OUTCOMES : Upon completion of this course, students should be able to: CLO 1. apply the principles of statics.
Chapter 4 The Laws of Motion. Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting.
Forces and Newton’s Laws of Motion. 4.1 The Concepts of Force and Mass A force is a push or a pull. Arrows are used to represent forces. The length of.
Engineering Mechanics
Namas Chandra Introduction to Mechanical engineering Hibbler Chapter 1-1 EML 3004C CHAPTER ONE General Principles.
Introduction to Dynamics. Dynamics is that branch of mechanics which deals with the motion of bodies under the action of forces. Dynamics has two distinct.
Chapter 4 The Laws of Motion. Classes of Forces Contact forces involve physical contact between two objects Field forces act through empty space No physical.
Chapter 4 -Day 7 The Laws of Motion. Hi Ho Silver!! Horse A (Appaloosa)leaves from point A and travels 30mph. Horse B (Arabian) leaves point A, 2 hours.
Copyright © 2010 Pearson Education South Asia Pte Ltd
Chapter 4 Forces and Newton’s Laws of Motion. 4.1 The Concepts of Force and Mass A force is a push or a pull. Contact forces arise from physical contact.
Physics 111: Mechanics Lecture 4
Engineering Mechanics: Statics
Chapter 4 The Laws of Motion. Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting.
Chapter 5 The Laws of Motion.
Raymond A. Serway Chris Vuille Chapter Four The Laws of Motion.
General Principles 1 Engineering Mechanics: Statics in SI Units, 12e Copyright © 2010 Pearson Education South Asia Pte Ltd.
MECHANICS Ms. Peace Introduction. Sequence 1.1 What is Mechanics? 1.1 What is Mechanics? 1.2 Fundamental Concepts and Principles 1.2 Fundamental Concepts.
Introduction to Dynamics. Dynamics is that branch of mechanics which deals with the motion of bodies under the action of forces. Dynamics has two distinct.
Forces and Newton’s Laws of Motion. A force is a push or a pull. Arrows are used to represent forces. The length of the arrow is proportional to the magnitude.
1 Chapter 4 The Laws of Motion Classes of Forces Contact forces involve physical contact between two objects Field forces act through empty.
Chapter 4 The Laws of Motion.
Raymond A. Serway Chris Vuille Chapter Four The Laws of Motion.
Engineering Mechanics Statics. Introduction Mechanics - the physical science which describes or predicts the conditions of rest or motion of bodies under.
ERT 146 Engineering Mechanics Ms Siti Kamariah Md Sa’at School of Bioprocess Engineering, UniMAP
Chapter 4 Forces in One Dimension. Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting.
FORCES AND CIRCULAR MOTION. A. Definition: a push or pull acting on a mass 1. Force is a vector quantity with both magnitude (numeric value) and direction.
The Laws of Motion. Classical Mechanics Describes the relationship between the motion of objects in our everyday world and the forces acting on them Describes.
Lecture 2 Objects in Motion Aristotle and Motion Galileo’s Concept of Inertia Mass – a Measure of Inertia Net Force and Equilibrium Speed and Velocity.
Introduction.
Chapter 4 The Laws of Motion.
Objectives: Write the equation of motion for an accelerating body.
Kinetics of Particles: Newton’s Second Law
Chapter Four The Laws of Motion.
How Forces Affect Motion
Copyright © 2010 Pearson Education South Asia Pte Ltd
FORCE A force is any influence that can change the velocity of a body. Forces can act either through the physical contact of two objects (contact forces:
Physics: Principles with Applications, 6th edition
Chapter 12: ALL ABOUT MOTION
CE 102 Statics Chapter 1 Introduction.
Introduction.
Chapter 1 - General Principles
Static and Dynamic Chapter 1 : Introduction
Introduction.
Chapter 4 Newton’s Laws.
Chapter 5 The Laws of Motion.
Isaac Newton ( ) Newton’s Laws of Motion
Chapter 4 The Laws of Motion.
Introduction.
Forces and Newton’s Laws of Motion
1 Course Code: SECV1030 Course Name: Engineering Mechanics Module 1 : Static.
Newton’s Laws Governing Motion
Introduction.
Petroleum and Mining Engineering Department
General Principles.
General Principles 4/10/2019.
The Laws of Motion (not including Atwood)
Introduction.
CHAPTER 1: INTRODUCTION & STATICS OF PARTICLES
Presentation transcript:

What is statics? Lecture 1 Branch of physical sciences concerned with the state of rest or motion of bodies subjected to forces is called Mechanics. The following diagram shows that Statics stands under solid mechanics of rigid bodies. 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. A body is considered rigid when the changes in distance between any two points within its body are negligible Deformable body: A body is considered deformable when the changes in distance between any two of its points cannot be neglected.

Lecture 1 What is statics? 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.  Statics is used to calculate forces in systems that don’t move, or move at constant velocity.  The application of physics to study motion is known as dynamics.

What is Statics? Relation between forces and displacements Lecture 1 What is Statics? Relation between forces and displacements F x Determine the components of a force in rectangular or nonrectangular coordinates. Determine the resultant of a system of forces. Draw complete and correct free-body diagrams and write the appropriate equilibrium equations from the free-body diagram. Determine the support reactions on a structure.

What is Statics? Internal reaction: Friction: Lecture 1 Internal reaction: Determine the internal reactions in a beam, Draw correct shear-force and bending moment diagrams, and Write equations for the shear-force and bending moment as functions of position along the beam. Friction: Analyze systems that include frictional forces.

What is Statics? Trusses: Centroid: Moment of Inertia: Lecture 1 Determine the connection forces in trusses and in general frame structures. Centroid: Moment of Inertia: Locate the centroid of an area. (center of mass or center of gravity) Calculate the mass moment of inertia, and the area moment of inertia.

Definitions Lecture 1 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. Gravitational, electrical and magnetic forces do not require direct contact. Force is characterized by magnitude, direction and point of application. Forces treated in mechanics as concentrated are in fact the resultants of corresponding systems of distributed forces.

Definitions Particle: Lecture 1 An object having mass but the size is neglected. = m If rotational effects can be neglected for a particular body, then that body can be treated as a single particle with mass of the body concentrated at one point. Examples: The Earth might be considered a particle if we were studying its orbit around the Sun. Travelled distance is too long compared to the car size, so the car treated as a particle. A cannon ball shot through the air could be treated as a particle; the same ball rolled along the ground would have to be considered as a rigid body of a given radius.

Basic Dimensions and Unit of Mechanics Lecture 1 Basic Dimensions and Unit of Mechanics The dimensions that are independent of all other dimensions are termed primary or basic dimensions, and that which are developed in terms of the basic dimensions are called secondary dimensions. The most convenient ones include the dimensions of length, time and mass [ MLT ]. The other units are described in terms of basic dimensions are termed the secondary dimensions. Length: It is a term or concept for describing size and dimensions of bodies or materials in space, without such measurement it can’t be acquiring a precise dimensions of them. Thus, the other aspects of size, such as area and volume can be formulated in terms of the standard by the methods of plane and solid geometry. This standard is called a unit of the dimension length. Many types of units are actually employed around the world; the most utilized types are the meter in SI unit and the foot in British unit.

Lecture 1 Mass: Mass can be determined from two different actions of bodies. To study the first action, suppose we have two hard bodies of different size and shape … etc at the earth’s surface. If these bodies are attached to identical springs, each spring will extend some distance ( l1 and l2 ) as a result of the attraction of gravity for these bodies. Now, if we stretch these two bodies downward an equal distance and release them at the same time, they will begin to move in an identical manner. If these bodies have same mass they will stretch to same extended distance. So, the property of mass characterizes a body both in the action of gravitational attraction and in the response to a mechanical disturbance [ It is a measure of the inertia of a body, which is its resistance to a change of velocity ]. The unit of mass in SI system is the kilogram ( kg ) which is approximately equal to the mass of [ 0.001 m3 ] of water, and in British unit the mass unit is the slug which is equal to 32.2 pound mass ( lbm ).

Time: Lecture 1 Secondary Dimensional Quantities Change of Units The time defined as a concept of description, ordering or flow of events passed during our life. So, to define an event, it is not sufficient to indicate or mention its position in space, thus the Time of that event should also be given. The rotation of the earth around itself serves as a good measure of time, but a smaller units is needed in engineering, this unit is generally the second which is an action repeatable 86,400 times a day [ 1 sec = 1/86,400 of a mean solar day ]. Secondary Dimensional Quantities When physical acts or processes are described in terms of basic dimensions by the use of suitable definition [ for instance velocity is defined as a distance divided by the time interval ] these quantities are called secondary dimensional quantities. Change of Units To change units from one type to another that may be needed during computation of some mechanical problems, for instance we want to change the meter into foot or inch to centimeter. In such cases we must replace the unit in question by a physically equivalent number of the new units. These must not be taken as algebraic relation but simply as indications of physical equivalences, and it can be written or expressed in another way: The unity on the right side of these relations indicates that the numerator and denominator on the left side are physically equivalent and have ( 1 to 1 ) relation.

What you need to know from Physics! 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.

Newton’s Three Laws of Motion 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. m If F is applied to a particle of mass m then: F = m. a

Newton’s Three Laws of Motion Third Law: To every action there is always opposed an equal reaction , or the mutual forces of action and reaction between two particles are equal, opposite and collinear.

Newton’s Laws of Gravitational Attraction The gravitational law of attraction states that, two particles (objects) will be attracted toward each other along their connecting line with a force whose magnitudes are proportional to the product of their masses and inversely proportional to the square distance between the particles. Or, by inserting the constant of proportionality ( G ), and rearranging the above equation to yield: Where: F = force of gravitation, G = universal constant of gravitation G = 6.673 × 10-11 m3 kg-1 s-2 m1, m2 = masses of two particles, r = distance between two particles.

Newton’s Laws of Gravitational Attraction The relation between the earth with any of the bodies on the earth, it could be considered each of the earth and each of these bodies as a particle, its mass concentrated at its center of gravity, this action is called the weight of the particle on the earth’s surface. According to this law, an object's weight is defined by:                       in which: m = mass of object M = mass of earth r = distance from center of earth to particle g = 9.81 m.s-2 (determined at sea level and at a latitude of 45o which is considered “standard location”).