Engineering EGR11 Unit 1; Topic 4 Introduction to Engineering Mechanics Today’s Lesson Learning Goals (WALT) • Get familiarized with the Introduction to Statics unit • Reviewing of units (base and derived) and metric prefixes Justification ( TIB ) • Engineers need to be completely competent in all metric units of measure Success Criteria (WILF) • You can convert between any and all metric base units • You can convert between squared and cubed quantities • You can convert derived units Your Reference Guide to the next three years... All our combined efforts will be working towards meeting the requirements of the curriculum syllabus Get yourself a copy of this curriculum document Get to know it!! Unit 1: Topic 4: Intro to Mechanics Topic 5: Intro to Materials Preview Questions 1. What are the base units in the SI system? 2. What is the difference between base units and derived units? Give an example for each. 3. Differentiate between scalar and vector quantities. 4. Give three examples of scalar quantities. 5. What four features define a vector? 6. What is force? 7. What is Newtons first Law? 8. What are the units of measure for forces? Eng Syllabus - Unit 1, Topic 4 Mechanics What are the main areas of study? MOMENTS UNDERSTANDING MECHANICS FORCES AND NEWTON'S LAWS OF MOTION Topic 4 – Intro to Engineering Mechanics DEFINITIONS ADDITION OF MOMENTS, SOLVING REACTIONS HORIZONTAL AND VERTICAL COMPONENTS VECTORS AND SCALAR QUANTITIES GRAPHICAL SOLUTIONS UNITS AND CONVERSIONS TRIGONOMETRY AND PYTHAGORAS GRAVITY, WEIGHT, MASS, DENSITY CONCURRENT AND NON - CONCURRENT ANALYTICAL SOLUTIONS DEFINITION AND CALCULATIONS TENSION AND COMPRESSION Eng Syllabus - Unit 1, Topic 4 Mechanics What are the main areas of study? MOMENTS UNDERSTANDING MECHANICS FORCES AND NEWTON'S LAWS OF MOTION Topic 4 – Intro to Engineering Mechanics DEFINITIONS HORIZONTAL AND VERTICAL COMPONENTS VECTORS AND SCALAR QUANTITIES GRAPHICAL SOLUTIONS UNITS AND CONVERSIONS TRIGONOMETRY AND PYTHAGORAS GRAVITY, WEIGHT, MASS, DENSITY CONCURRENT AND NON - CONCURRENT ANALYTICAL SOLUTIONS DEFINITION AND CALCULATIONS TENSION AND COMPRESSION ADDITION OF MOMENTS, SOLVING REACTIONS Some key definitions for this unit Engineering Mechanics • Covers the effects of forces on the condition of machines , structures, and their components when at rest or in motion • Particular focus on the mechanics of rigid structures, machines and components Statics • Concerned with the analysis of loads ( forces+moments ) acting on structures that are in static equilibrium with their environment. • Static equilibrium means no acceleration – so at rest or in constant motion. Dynamics • Concerned with the study of forces (linear) and torques (rotational) and their effects on the motion of an object Eng Syllabus - Unit 1, Topic 4 Mechanics What are the main areas of study? MOMENTS UNDERSTANDING MECHANICS FORCES AND NEWTON'S LAWS OF MOTION Topic 4 – Intro to Engineering Mechanics DEFINITIONS HORIZONTAL AND VERTICAL COMPONENTS VECTORS AND SCALAR QUANTITIES GRAPHICAL SOLUTIONS UNITS AND CONVERSIONS TRIGONOMETRY AND PYTHAGORAS GRAVITY, WEIGHT, MASS, DENSITY CONCURRENT AND NON - CONCURRENT ANALYTICAL SOLUTIONS DEFINITION AND CALCULATIONS TENSION AND COMPRESSION ADDITION OF MOMENTS, SOLVING REACTIONS Units in the Metric and SI Systems Compare base units for each measurement system Engineering uses the SI system (also known as MKS – metres kilograms seconds) There are 7 SI Base Units With a partner, identify them EGR will use these units only Base Units and Derived Units • Base units are those which cannot be derived from other physical quantities • Time • Distance • Temperature • There are seven (7) • Derived Units are those which are defined by a combination of base units • Examples include • Velocity • Power • Pressure Units and SI Prefixes Familiarise your self with common units used within engineering, such as gravity, time, force, weight/ mass, distance, speed, are all important to understand • It is common practice for engineers to deal with large numbers Using prefixes makes that task easier • SI prefixes, these are expressed 10 3 ,10 6 ,10 9 and 10 - 3 ,10 - 6 ,10 - 9 often assist in writing answers to questions without writing several zeros Metric System Prefixes LARGER unit of measure SMALLER unit of measure BASE BASE Converting between metric prefix units STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger Conversion Practice 1, base units STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger Conversion Practice 1, base units STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger Conversion Practice 1, base units STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger 1 Megapascal (MPa) = 1 000 000 Pascals (Pa) 1 Gigapascal (GPa) = 1 000 000 000 Pascals (Pa) MPa Pa 50000000 957430 6.7 45 160 000 000 000 25.17 Task: Take a moment to do the conversions in your notebooks STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent change between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger Conversion Practice 2: Pascals (stress) Conversion Practice 2: Pascals (stress) 1 Megapascal (MPa) = 1 000 000 Pascals (Pa) 1 Gigapascal (GPa) = 1 000 000 000 Pascals (Pa) Task: Take a moment to do the conversions in your notebooks MPa Pa 50 50000000 0.957 957430 6.7 6 700 000 45 45 000 000 160 000 160 000 000 000 25.17 25 170 000 STEPS to FOLLOW 1. Determine if the new unit you are converting to is smaller or larger 2. Determine the exponent change between the unit prefixes 3. Move the decimal place the same number as the exponent , Ø to the right if the new unit is smaller Ø to the left if the new unit is larger