General Physics Q2 Notes PDF

GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 W1: ELECTRICITY A Electricity Presence and flow of electric charges Control the amount of electricity A1 Electri...

GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 W1: ELECTRICITY A Electricity Presence and flow of electric charges Control the amount of electricity A1 Electric Charge (q) Semiconductor - between the conductor and insulator Superconductors The electrical nature of matter which is ○ Mostly metals - metalloids inherent in its atomic structure (carried by elementary particles) Two general types: ○ Positive ○ Negative Coulomb - SI unit of charge Conductor Parameters in an Electric Circuit Any material that allows electric current to pass through it Voltage (V)- the difference in potential energy between two points in the electric circuit. Current (C)- the amount of flow of electric changes Resistance (R) - a material’s tendency to resist the flow of electric changes. Voltage Across a Battery Insulator The potential difference (electric potential), or voltage, across the two ends, or terminals, of a battery ranges Any material that does not allow from about 1.5V for a small battery to electric current to pass through it about 12 V for a car battery ○ Like the protective coating on Most batteries are electrochemical wires cells–or groups of connected cells–that convert chemical energy into electrical energy. PAGE 1 Mirakelly Monique R. Ng – 12HA-12 – UST - SHS  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Electromotive force (EMF) is defined as the electric potential produced by either electrochemical cell or by changing the magnetic field. A generator or a battery is used for the conversion of energy from form to another. Difference between EMF and Voltage EMF - the electromotive force is the type of Electric Potential And Potential Difference energy which forces a unit positive charge to move from the positive to the negative terminal Batteries “lift”charges to a higher of the source. It separates the two charges from potential each other. There is a Potential Difference because VOLTAGE - the difference in electric potential each coulomb of charge has a different between two points. The voltage between two potential energy at either end of the points is equal to the work done per unit of battery. charge against a static electric field to move a test charge between two points PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 2  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Electric Current (I) More precisely, the electric current in a wire is defined as the net amount of an electric current is a flow of charged charge that passes through the wire’s particles or current full cross section or any amount per A current in a metal is due to the unit time. movement of electrons Thus, the current I is defined as: Current is measured using an ammeter. An ammeter measures the rate flow of charge. The unit of current is the Ampere (A). (1 amp. Of current = 1 coulomb of charge per second) Electric current is only present if there is electric potential between two points If the charges move around the circuit in the same direction at all times, the current is said to be direct current (DC). ○ E.g. batteries If the charges move first one way and then the opposite way, the current is said to be alternating current (AC) - changes its direction each half cycle. ○ E.g. household current PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 3  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Resistivity (ρ) Resistivity is the property of the conductor due to which it offers resistance to the flow of current through it The better the conductor, the less its resistance. SI unit for resistivity is Ohm-meter (Ω-meter) Resistance (R) The resistance of a conductor is a measure of the opposition it offers to the flow of electric current; SI unit of resistance is Ohm(Ω) A wire or an electrical device that offers resistance to electrical flow is called a resistor. The resistance of a component causes electrical energy to be converted into heat Resistance of a component causes electrical energy to be converted into heat Resistance depend on the conductor’s ○ Length ○ Cross-sectional area ○ Type of material (e.g metals) ○ temperature Resistors A resistor is an electrical component that limits on regulates the flow of electrical current in an electronic circuit PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 4  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 A2 OHM’s LAW The higher the electric potential difference or voltage between two points in a circuit, the more charges can move between these points. Current (I) is directly proportional to voltage (V) and inversely proportional to resistance ® This relationship as discovered by George Ohm ↑V ↓I ↓V ↑I ↑R ↓I PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 5  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 ↓R ↑I ↑R ↑V ↓R ↓V In summary Voltage, also called electromotive force, is a quantitative expression of the potential difference in charge between two points in an electrical field. Any flow of charge such as this is callen an electric current. Resistance is the hindrance to the flow of charge. (Ohm) PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 6  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Energy - Power Power = energy per unit time (Watt) Energy = power x time ○ E.g. kilowatt-hour (kWh) - used in electrical energy costs , A3 Electric Power (P) The rate at which electric energy is converted into another form such as mechanical energy, heat, or light. The power consumed by an electric appliance is equal to the product of the current flowing through it and the voltage across it. P=IV SI unit: Watt (W) The product of current (amp) and voltage (volt) The product of current (amp) and voltage (volt) PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 7  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Direct Current Circuit Direct current (DC) is an electric current that is uni-directional, so the flow of charge is always in the same direction (from + to -) The closed path in which the direct current flows is called in DC circuit. It is mostly used in low voltage applications The resistor is the main component of the DC circuit. W2: Electric Circuits B Electric Circuits Any path along which current and electron can flow Unbroken path of material that carries electricity It consists of an energy source and an energy consuming device which are connected by conducting wires through which electric charges move Within a battery, a chemical reaction occurs that transfers electrons and charges from one terminal to another terminal. The maximum potential difference across the terminals is provided and maintained by the electromotive force (EMF). PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 8  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Voltage Rise = Voltage Drop Series Circuits Voltage Rise - supplied by battery Encounter resistors = Voltage Drop Series: two or more loads are linked Voltage Rise = Total of each Voltage Drop across a single loop of wire SERIES CIRCUIT (PROBLEM SOLVING) ○ The current is the same at all points in a series circuit ○ Total resistance to current in this circuit is the sum of the individual resistances along the path. PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 9  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Parallel Circuits Parallel: different loads are situated on different wire loops Junctions ○ Components connected in parallel with each other all have the same voltage ○ Each path operates independently of the other paths ○ Total current in this circuit equals the sum of the currents in its parallel branches ○ As the number of parallel branches is increased, resistance of the circuits is decreased. Parallel circuits are prone to overloading PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 10  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 PRACTICE EXERCISE: PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 11  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Grounding a negatively charged electroscope involves the transfer of electrons from the electroscope to “the ground” Grounding a positively-charged electroscope involves the transfer of electrons from “the ground” to the electroscope. GROUND - grounding to the earth, to pass through the electric current, that can prevent electric shock C Some Medical Application of Electric Physiological Effects of Electric Current Current Depends on the resistance of one’s body (depending on its condition: wet/dry) The severity of electrical injury depends on the magnitude of the current and the parts of the body through which the moving charges pass. Mild tingling sensation: 0.001 A Muscle spasms (“can’t let go”): 0.01-0.02 A Fatal (heart fibrillation) 0.2 A PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 12  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 W3: WORK ENERGY AND POWER D WORK Is done when there is motion (scalar quantity) Result of a force acting upon an object to case a displacement of the object ○ Force ○ Displacement ○ Cause In order for a force to qualify as having done work on an object, there must be a displacement and the force must be the cause of that displacement. Determine whether or not they represent work: PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 13  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Types of Work Work against inertia ○ Applying force to cause change in motion (e.g. throwing/kicking a ball) ○ W = Fd= mgh Work against gravity ○ Involves height ○ W= mgh Work in going up and going down will always be equal no matter how slow or how quick the person moved. PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 14  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 ○ Work = Energy Both are scalar quantities; same unit (Joules) Types: ○ Kinetic energy ○ Potential energy Potential Energy The energy of objects at rest; stored energy ○ Gravitational potential energy ○ Elastic potential energy Elastic Potential Energy Energy stored in elastic materials as the result of stretching or compressing ○ E.g rubber bands, bungee chords, trampolines, springs, arrow drawn into a bow E ENERGY Ability to do work; expressed in Joules No energy, no work is done Property of a body or system of bodies by which work can be done or performed The energy possessed by a body is equal to the total work it can do PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 15  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Gravitational Potential Energy GPE of an object equals its weight ties its height above the ground GPE is stored as the result of the gravitational attraction of the Earth for the object GPE= mgh GPE is directly proportional to both mass and height. Kinetic Energy The energy of objects in motion ○ Once the object at rest starts moving, the PE it has will then be converted to KE SAMPLE PROBLEMS PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 16  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 Work-Energy Theorem Work = Energy The theorem states that the net change in KE of a particle (system) is a equivalent to the sum of work done by all types of external forces The kinetic energy of an object increases as a result of the amount of work. Work done on an object transfers energy to the object. PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 17  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 The longer the time, the lesser the power F POWER extended ↑t↓p The rate at which work is done ↓ t↑ p The rate at which energy is expended Power is the amount of work done divided by the time it takes to do it. Power is the energy expended/transformed divided by the time it takes to do it. Power is the energy expended/transformed divided by the time it takes to expend it. SI uniform power = Watt (W) 1 horsepower = 550 ft-lb of work/second = 746 watts or 0.746 kilowatt Power is the rate at which energy is transferred or the rate at which work is done. Work and Power Work has nothing to do with the amount of time the force acts to cause the displacement ○ E.g A person going up and down the stairs For power, time is inversely proportional. Therefore, the shorter the time the work is done, the higher the power extended. PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 18  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 19  GENERAL PHYSICS 12HA-12 1st 1SEMESTER, Q2 – Ma’am Lalaine Prado – ‘24-’25 TABLE TITLE KEY TERM Definition Example KEY TERM Definition Example B1 ABOUT THIS TEMPLATE Originally made by kw0ndys Inspired by my own school notes and includes design elements from Google to improve its look and functionality. B2 REMINDERS This template is designed exclusively for your personal use. DO NOT RESELL OR REUSE. This template is fully customizable. If you have suggestions for improvements, please do not hesitate to let me know. Your feedback is valuable and helps me enhance the quality of this template. The design and content of this template are unique to my work, and any resemblance to other templates is unintentional. A1 HOW CAN I ACCESS THIS TEMPLATE? The original copy of this template is set to “view only” to ensure it remains unedited and intact. 1. Go to “File” at the top left corner. 2. Select “Make a copy”. 3. Rename your file to avoid confusion. 4. Click “OK” to save your copy. PAGE Mirakelly Monique R. Ng – 12HA-12 – UST - SHS 20