Physics Final Review PDF

Physics Final review Section 0 - scientific notation, unit conversion and significant digits Scientific notation: -​ Is a way if writing a very large and small (decimal) numbers -​ You are required to use scientific notation in all high school courses -​ The way of writing it is 6.022...

Physics Final review Section 0 - scientific notation, unit conversion and significant digits Scientific notation: -​ Is a way if writing a very large and small (decimal) numbers -​ You are required to use scientific notation in all high school courses -​ The way of writing it is 6.022 x 10^23 avogadro's number -​ We use this as a shorthand to avoid writing out extremely long numbers -​ If we didn't use scientific notation it would be too long and inconvenient Significant digits -​ The amount of digits you should have based on how many numbers you have in your equation Unit conversion: Ex: Ex: Section 1 (\Motion, velocity, acceleration) ​ Motion -​ When something is moving ​ Uniform motion -​ Something that is moving at a constant rate / constant speed. -​ It is not slowing down or speeding up. Its motion is in uniform Formulas/ calculations: Speed Distance Time Units : Speed - usually m/s Distance - typically meters Time - Typically seconds ​ Average velocity -​ General velocity, trip as a whole (the tidal distance and tidal time of the trip) ​ Instantaneous Velocity -​ Specific velocity, The number on the speedometer at any given point in time Ex: Average velocity on a trip to calgary would be 100 km/h Instantaneous velocity could be 80km/h on whitemud drive or 110 km/h on henday Uniform motion graphs: Distance and time graphs: Speed and time graphs Slope of a graph -​ Is how steep a line is -​ The formula for this us rise over run (Rise/Run) or (Y2-Y1/X2-X1) -​ Slope is defined as the change in Y over the change in x -​ To calculate slope take any two points on the graph and divide the difference in they're y values by the difference in they're x values For a distance time graph: -​ Diagonal going up is constant speed (positive slope) -​ 3 things Zero slope -​ A horizontal line that indicates that an object is at rest (it is not moving)\ Positive slope -​ Positive slope is moving away from the origin at a constant speed (moving up) Negative slope -​ Moving towards the origin (moving down) Graphing: Needs a name Needs to indicate the scale of the graph (example: speed is in m/s and time is in seconds) Graph with appropriate units TIME ALWAYS GOES ON THE X AXIS Speed vs time graphs -​ Time will always be on the x axis -​ For a speed vs time graph when its uniform motion it will always be a horizontal line -​ The area under a speed vs time graph is equal to the distance traveled (because area is width times length and to get distance its speed times time) Lesson 2 uniform motions- vectors Scalar vs. vector ​ Scalar -​ Has magnitude/ size but no direction -​ Examples are mass, time, distance, work ​ Vector -​ Magnitude and direction -​ Examples are velocity, displacement, acceleration Distance vs displacement ​ Distance -​ Is a scalar quantity -​ Distance has no direction (total distanced move) ​ Displacement -​ Is a vector quantity -​ It contains direction and change in position (initial - final) Calculating distance traveled -​ Each leg of the journey is added together Calculating Displacement -​ Is added together but you have to say if its positive or negative (front add, back, subtract) -​ North east is add/frontwards west south is subtract/backwards Speed vs velocity ​ Speed -​ Is a scalar quantity -​ Distance is used ​ Velocity -​ Is a vector quantity -​ Displacement is used Formula: Position time graphs -​ Exact same as a distance time graph but instead of distance its position (displacement) -​ From the slope we can determine direction ​ Going up means going frontwards (north, east) ​ Going down means going backwards (south and west) ​ Horizontal means not moving at all Lesson 3 acceleration ​ Acceleration -​ the change in velocity over a specific time interval. It is a vector quantity (has a direction) -​ The units for acceleration are m/s^2 because -​ How much faster your going per second -​ Page 25 Formula/equation: ​ The change in velocity/time = acceleration  ​ When the initial velocity and acceleration are in the same direction, the car is speeding up ​ When the initial velocity and acceleration are in opposite directions the car is slowing down ​ Acceleration frontwards north or east is positive ​ Acceleration backwards south or west is negative Acceleration due to gravity -​ Gravity = 9.81m/s^2 -​ Mass does not affect the rate which something falls on the ground Accelerated motion graphs -​ A distance x time graph will have a curved line going up if its accelerating -​ Curved line going down if its decelerating (slowing down) -​ A velocity time graph will be a sloped straight line. The slope of the line will be its acceleration -​ Position time graphs going straight up means going forward at a constant rate -​ Velocity time graph going straight up means going faster at a constant rate Summary Distance/time Position time Speed time Velocity time Accelerated graphs graphs graphs graphs motion graphs -Going diagonal -Instead of -the area under it -diagonal going up -distance time graphs straight up means distance its is the distance means getting will have a curved line going up if its its moving at a displacement -horizontal line faster at a accelerating constant speed -from the slope we means constant constant rate -it will have a curved (positive slope) can determine speed -diagonal doing line going down if its -When it is a direction down means its decelerating horizontal line it -going up means decelerating -velocity time graphs does not move frontwards -horizontal means will have a straight - when its straight -horizontal means its not moving diagonal line if its going down it not moving accelerating(going uo) means its moving -going down -it will have a straight diagonal line going towards the origin means backwards down if its decelerating (negative slope) Lesson 4: work, energy and force Work -​ Work is a measure if the amount of energy transferred from one object to another -​ Energy is the ability to do work -​ Energy = joules | 1J = 1 kg x m^2/s^2 | ​ When you lift a box: you do work on the box ​ You lose energy when you lift up the box ​ The box gains energy. Its higher up and stores potential energy ​ When you push a box you do work on the box ​ You lose energy when you push the box ​ The box gaines energy , its moving, meaning it has gained kinetic energy Force -​ A force is a push or pull applied to a object -​ Force is measured in newtons (N) -​ For is a vector quantity (has direction) What is a newton -​ Force is measured in a derived unit called newtons 1N = 1kg m/s^2 Balanced forces -​ When forces are balanced the object will remain stationary or move at a constant speed (no acceleration) Unbalanced forces -​ When forces are unbalanced an object will accelerate in one direction Work -​ For work to occur 3 conditions must be met 1.​ The object must move 2.​ There must be applied force 3.​ Force and displacement must be in the same direction Formula : Section 2 energy and energy conversions Law of conservation of energy -​ Energy cannot be created nor destroyed -​ Energy can only be transformed or converted into other forms Types of energy ​ Kinetic energy (energy of MOTION. Ex: a car moving) -​ Thermal energy (kinetic energy of moving particles that cause heat) -​ Electrical energy (kinetic energy of flowing electrons through a wire) ​ Potential energy (energy stored, the potential. Ex: a pen waiting to drop) -​ Chemical energy (potential energy stored in the chemical bonds of compounds -​ Elastic energy ( potential energy stored in spring like object when it is stretched or compressed ) -​ Gravitational energy (energy that is stored in an object due to how high it is above the ground -​ Nuclear energy (potential energy that is stored in the nucleus of atoms. Energy can either be released during fusion or fission  ​ Mechanical energy (kinetic + potential energy caused from motion and position) ​ Sound energy - form of energy traveling through sound waves we can hear ​ Light energy (solar energy) - Form of energy fund in photons that we can see solar energy comes from the sun Energy conversions -​ Flashlight (chemical - light or heat) -​ Windmill (kinetic - electrical) -​ Car engine (chemical - kinetic) -​ Solar panel (light - electrical) Voltaic pile -​ First electrical battery -​ Converts chemical energy into electrical energy -​ It was invented by italian physicist Alessandro volta James prescott joule -​ Performed experiments to demonstrate energy transformations -​ His most famous experiment showed that a falling object contains energy ​ A series of weights was attached to a pulley that fell. This caused the axle to rotate which spun in the water to increase the temperature Lesson 6 Mass vs weight ​ Mass -​ Is a scalar quantity -​ Measured in kg -​ An object's mass is consistent throughout the universe ​ Weight -​ Is a vector quantity -​ Measured in newtons -​ Weight = force of gravity acting on a object (Fg) Weight is science depends on 2 factors -​ The mass of an object (m) -​ The acceleration due to gravity Formula ​ Gravitational potential energy -​ Due to an object's position above earth , these factors determine how much gravitational potential energy an object has 1.​ Height of an object (h) in meters 2.​ Mass of an object (m) in kilograms 3.​ Acceleration due to gravity (m) m/s^2 Formula: Rearranging the equation Lesson 7 Kinetic energy ​ Kinetic energy is associated with the motion of an object and depends in two factors 1. Mass of an object (m) 2. Speed the object is moving (v) ​ Formula: Rearranging: Solving for mass: Solving for Speed (v) Graphs and relationships ​ Energy is directly proportional to mass (they both increase or decrease) ​ Energy is directly proportional to speed(they both increase or decrease) Lesson 8: Mechanical energy Conservation of energy: Energy is a isolated system, cannot be created nor destroyed -​ Mechanical energy is the energy due to the motion and position of an object -​ Mechanical energy is the SUM of the kinetic and potential energy of an object ​ Highest point = MORE potential energy, LOW kinetic ​ Middle = change/exchange of energy ​ Lowest point = LEAST potential energy, HIGH kinetic A graph of mechanical energy will always show a “trade off” between potential and kinetic energy ​ If there is no friction, the total mechanical energy will stay constant ​ If there is friction, some mechanical energy will be lost as thermal energy ​ When an object changes position, potential energy is transformed into kinetic ​ When an object stops moving, kinetic energy is transformed into potential energy Mechanical energy -​ Since energy is conserved, this means that Section 3 Thermodynamics and efficiency Lesson 9 ​ System -​ Interconnected parts ​ Isolated system -​ No energy or matter is exchanged ​ Closed system -​ No matter is exchanged but energy is exchanged in the cell ​ Open system -​ Matter and energy is exchange in and out of the cell The only perfectly isolated system is our entire universe First law of thermodynamics = law of conservation of energy -​ The total energy in a system remains constant -​ Whenever energy is added to a system, some will be used to power the system, but some amount of energy is lost in some other form (usually heat) Second law of thermodynamics = describes the direction of energy flow in a natural process -​ Unless forced to do otherwise, energy will naturally flow from hot objects to cold objects Heat engines - uses the natural flow of energy to do work (eg turn a turbine) Heat pumps - a device that forces heat from cold to hot (ex. A refrigerator) is called a heat pump -​ In order to force energy to go in the opposite direction work must be done Efficiency (how useful) -​ The measurement of how effectively a machine converts energy input into a useful energy output. -​ It is described as a percentage, a perfect machine being 100% ​ More useful output energy than wanted output energy = high efficiency ​ Less useful output energy than wasted output energy = low efficiency Formula