Introduction to Pre-VCE Physics 2025 PDF

INTRODUCTION TO PRE-VCE PHYSICS WHAT IS PHYSICS?  WHAT IS PHYSICS? The science of explaining Nature (the Physical World) WHAT DO YOU ALREADY KNOW ABOUT PHYSICS? TERMS YOU MIGHT HEAR ABOUT IN PHYSICS  BRANCHES OF PHYSICS Classical Physics...

INTRODUCTION TO PRE-VCE PHYSICS WHAT IS PHYSICS?  WHAT IS PHYSICS? The science of explaining Nature (the Physical World) WHAT DO YOU ALREADY KNOW ABOUT PHYSICS? TERMS YOU MIGHT HEAR ABOUT IN PHYSICS  BRANCHES OF PHYSICS Classical Physics Modern Physics Mechanics Atomic Physics Motion, Forces etc. Solid State Physics Heat & Thermodynamics Electronics & Sound & Waves Photonics Electricity & Magnetism Relativity (Electromagnetism) Nuclear & Particle Optics (Light) Physics  WHAT DOES PHYSICS DEAL WITH ANYWAY? The BIG The SMALL Examples: Examples: Gravitation Electronics Cosmology – the Quantum Mechanics study of the Universe String Theory  HOW DOES PHYSICS DEVELOP? What it’s NOT What it is! A set of facts! Observations Theories Models ALL DESIGNED TO EXPLAIN our observations  SEMESTER OUTLINE Topic 1: Motion (and forces) Topic 2: Work, Energy & Power Topic 3: Electricity Extended Practical Investigation Forces of nature with Brian Cox. https://youtu.be/S1eK_frCTCE?si=dUn-v75kz TeyiyT7  D I S C U S S I O N Q U E S T I O N S F O R ‘ F O RC E S O F N AT U R E ’ What are the four fundamental forces? Which force is the weakest? What significant contribution did Maxwell make regarding electricity and magnetism? What force glues the nucleus together? What generates 98% of the mass of atoms? What is a positron? How can beta radiation (electrons) be emitted from a nucleus that doesn't contain electrons? What force is responsible for this? What are scientists recreating at the Large Hadron Collider at CERN and why?  FOUNDATION KNOWLEDGE The SI System Conversion of Units Standard Form Scalars & Vectors  THE SI SYSTEM “Systeme Internationale d’Units” The system is based on 7 The system has two important Fundamental Units, each of characteristics; which is strictly defined. Different units for the same physical quantity are related by All other units, so called factors of 10.(eg. mm; cm; km) S.I. System: DERIVED UNITS, are simply 7 Fundamental Quantities & their Units combinations of 2 or more of the Fundamental Units. Length: Mass: Time: Temperature: Luminous Amount of Charge: Unit: Unit: Unit Unit Intensity: Substance: Unit Metre Kilogram Second Kelvin Unit Unit Coulomb (C) (m) (kg) (s) (K) Candela (cd) Mole (M) Velocity: velocity - Unit Derived Unit Further reading ms-1 http://www.npl.co.uk/si-units/  DERIVED UNITS What are the units for Current? Velocity? Force Are these fundamental units or derived units. Explain  DERIVED UNITS Current? Charge (coulomb) Rate of flow (seconds) Coulomb per second = ampere (amp) Velocity? Distance (metres) Rate (seconds) Metres per second = ms-1 Force? Mass (kg) x acceleration (ms-2) kg x ms-2 = Newton COMMON METRIC PREFIXES  COMMON UNIT CONVERSIONS What common unit conversions do you think you will be expected to know?  SIGNIFICANT FIGURES  Significant figures should be considered in all calculations. The following guidelines apply to VCE Physics:  all digits in numbers expressed in standard form are significant, e.g. 4.320 x 10-6 has 4 significant figure  all non-zero numbers are significant, e.g. 42.3 has 3 significant figures  zeros between two non-zero numbers are significant, e.g. 4.302 has four significant figures  leading zeros are not significant, e.g. 0.0043 has 2 significant figures  trailing zeros to the right of a decimal point are significant, e.g. 42.00 has 4 significant figures. For numbers less than 1, 0.4 has 1 significant figure, 0.04 also has 1 significant figure whereas 0.40 has 2 significant figures and 0.400 has 3 significant figures  whole numbers written without a decimal point will have the same number of significant figures as the number of digits, with the assumption that the decimal point occurs at the end of the number, e.g. 400 has 3 significant figures. Therefore, a measured distance of 100 m will be considered as having three significant figures. SCALARS & VECTORS  SCALARS AND VECTORS All physical quantities can be divided into two broad groups based on what information you need for the quantity to make sense. These groups are called scalars and vectors. Vectors are represented by arrows.  SCALARS & VECTORS Scalar Quantities Have a MAGNITUDE only. E.g. Temperature (), Time (15 s), Mass (2.5 kg), Distance (150 m) Vector Quantities Have a MAGNITUDE and a DIRECTION E.g. Displacement (2.7 km West), Velocity (), Force (15 N downwards) Vectors are usually shown by ARROWS The length of the arrow represents the magnitude (SIZE) of the vector  COMPARING SCALAR WITH VECTORS SCALAR QUANTITIES VECTOR QUANTITIES Quantities that require magnitude Vector quantities require magnitude, and units only units and direction in order to make sense Scalars do not need direction Examples Examples: Position Time Displacement Distance Velocity Volume Acceleration Speed Force Temperature Momentum REPRESENTING VECTORS – SIGN CONVENTION  ADDING VECTORS Adding Vectors in One Dimension When two or more vectors are in the same dimension, it means the vectors are either pointing in the same direction or in the opposite direction. They are collinear (in line with each other). Vectors are added head to tail The resultant vector is drawn from the tail of the first vector to the head of the last vector