Vector Mechanics For Engineers: Statics Twelfth Edition PDF

SUBJECT: LECTURE: DATE: IMPORTANT (equations, laws, etc.) Vector Mechanics For Engineers: Statics Twelfth Edition NOTES...

SUBJECT: LECTURE: DATE: IMPORTANT (equations, laws, etc.) Vector Mechanics For Engineers: Statics Twelfth Edition NOTES Chapter 1 Introduction ©Renato Bordoni/Alamy © 2019 McGraw-Hill Education. All rights reserved. Authorized only for instructor use in the classroom. No reproduction or further distribution permitted without the prior written consent of McGraw-Hill Education.  SUBJECT: LECTURE: DATE: IMPORTANT (equations, laws, etc.) Contents What is Mechanics? Systems of Units Method of Solving Problems NOTES Numerical Accuracy Announcements: ◦ Chapter 1/this week- just an intro, won't be solving math problems yet ◦ Chapter 1 and 2 slides posted on Canvas Intro: ◦ How to be more prepared? Review fundamental physics concepts like Newton's Laws © 2019 McGraw-Hill Education.  SUBJECT: LECTURE: DATE: IMPORTANT What is Mechanics? (equations, laws, etc.) F=ma Mechanics is the study of bodies under the action of forces. Categories of Mechanics: Rigid bodies. NOTES Statics – bodies at rest or at constant velocity. Dynamics – accelerating bodies. Deformable bodies. Fluids – gas and/or liquid. Mechanics is an applied science, closely related to physics, so many of the concepts will build on that prior knowledge. Mechanics is the foundation of many engineering topics and is an indispensable prerequisite to their study. Need a good foundation including Newton's Laws © 2019 McGraw-Hill Education.  SUBJECT: LECTURE: DATE: need to convert *generally IMPORTANT Systems of Units (equations, laws, etc.) everything in a problem into SI base units Kinetic Units: length, time, International System of Units (SI): mass, and force. The basic units are length, time, and mass which are arbitrarily defined as The first three of the kinetic the meter (m), second (s), and kilogram units, referred to as basic (kg). Force is the derived unit, NOTESunits, may be defined Force is always in arbitrarily. The fourth unit, F = ma Newtons (N). referred to as a derived unit,  m 1N = (1kg ) 1 2  must have a definition  s  compatible with Newton’s U.S. Customary Units: 2nd Law, The basic units are length, time, and force which are arbitrarily defined as F = ma the foot (ft), second (s), and pound When solving a problem, we need to choose the same base units to get (lb). Mass is the derived unit, the same answers. F m= a 1lb 1slug = 1ft s © 2019 McGraw-Hill Education.  SUBJECT: LECTURE: DATE: Method of Solving Problems: Smart IMPORTANT Methodology (equations, laws, etc.) Start using the concepts you decided Write down all known info, then decide to use in part S. Write out speci c which laws/concepts you'll use to solve formulas you'll use. Solve equations for Strategy: the problem. Analysis: an answer/value. Include a clear statement of the The six fundamental principles are problem, figure(s) describing the applied to express the conditions of rest given information, and or motion of each body. The rules of NOTES specification of what is to be algebra are applied to solve the equations determined. Decide what concepts for the unknown quantities. apply and how they can be used to Does the answer make sense? What Reflect and Think: type of answer should we expect? solve the problem. What is physically realistic? Draw a gure (ex: FBD). Test for errors by verifying that the Modeling: units of the computed results are Create a separate diagram for each correct, body, showing all quantities test for errors by substituting given involved. In equilibrium analyses, data and computed results into clearly indicate all forces acting on previously unused equations, each body; such sketches are called always apply experience and physical free-body diagrams. intuition to assess whether results seem “reasonable”. © 2019 McGraw-Hill Education.  SUBJECT: LECTURE: DATE: IMPORTANT Numerical Accuracy (equations, laws, etc.) The accuracy of a solution depends on 1) accuracy of the given data, and 2) accuracy of the computations performed. The solution cannot be more accurate than the less accurate of these two. The use of hand calculators and computers generally makes the accuracy of the computations much greater than the accuracy of the data. Hence, the NOTES solution accuracy is usually limited by the data accuracy. That is, remember what you have learned about significant figures. As a general rule for engineering problems, the data are seldom known with an accuracy greater than 0.2%. Therefore, it is usually appropriate to record parameters beginning with “1” with four digits and with three digits in all other cases, that is 40.2 lb and 15.58 lb. In general, keep at least 2 decimal places, and just round the last 2nd place. Ex: In the course, round 12.345 to 12.35. In Chapter 2, we'll see worked out problems using the SMART Methodology. © 2019 McGraw-Hill Education.  SUBJECT: LECTURE: DATE: IMPORTANT (equations, laws, etc.) NOTES End of Chapter 1 © 2019 McGraw-Hill Education.