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SI Units

• There are 7 basic quantities and units.
• Electrical Current is measured in Amperes (A).
• Luminous Intensity is measured in Candela (cd).
• Temperature is measured in Kelvin (K).
• Mass is measured in Kilogram (Kg).
• Length is measured in Metres (m).
• Amount is measured in Mole (mol).
• Time is measured in Seconds (s).

Prefixes Used for Scalar & Vector Quantities

• Kilo equals 10^3.
• Deci equals 10^-1.
• Centi equals 10^-2.
• Milli equals 10^-3.
• Micro equals 10^-6.
• Nano equals 10^-9.

Forces And Energy

• Force is an agent that produces or tends to produce motion and/or rest.
• Speed is the distance moved in a given period of time.
• Average speed = distance moved/time taken.
• Speed is scalar (only magnitude).
• Velocity is speed in a certain direction, making it a vector.
• Velocity = displacement/time
• A vector has both magnitude and direction.

Acceleration

• Acceleration measures the rate of increase in velocity and is a vector quantity.
• Acceleration = increase in velocity/time taken.
• Deceleration, or Retardation, measures the rate of decrease in velocity.
• If an object decelerates at 3 m/s², its acceleration is -3 m/s².
• m/s² is the same as ms^-1 is more commonly accepted

Distance-Time Graphs

• Plotted to show the increase in distance over time.
• The gradient shows the velocity of the car.
• Gradient = (y2-y1)/(x2-x1).

Velocity-Time Graphs

• Velocity-time graphs show the changing velocity over time.
• Represents Time graph of a moving car.
• The gradient of a velocity-time graph is the acceleration of that specific object (same formula).
• The area under a velocity-time graph represents the distance that object has moved.

Equations of Motion

• Three main equations of motion:
  • V = U + AT
  • S = UT + ½ AT²
  • V² = U² + 2AS
• Where:
  • v = final velocity
  • u = initial velocity
  • s = distance
  • t = time
  • a = acceleration

Mass vs Weight

• Mass is the amount of matter present in a body.
• Weight is the force exerted on the ground.
• Mass is measured in Kilograms (Kg), where Weight is measured in Newtons (N).
• Mass is independent of weight where Weight is dependent on mass.
• Mass remains constant across different gravitational strengths.
• Weight changes across different gravitational strengths.
• Mass has no formula.
• Weight Formula: W=mg (g = gravitational strength).
• Mass is a scalar quantity where Weight is a vector quantity
• Mass is independent of gravity while Weight is dependent on gravity.
• Mass has no given direction while Weight is has given direction (downwards).

Gravitational Strength

• Gravitational strength of Earth is almost constant ≈ 9.8 m/s² or ms⁻².
• In free fall cases, a (acceleration) = g.
• Initial velocity (u) = 0.

Terminal Velocity

• An object only accelerates until it reaches terminal velocity.
• Terminal velocity represents the highest attainable velocity of an object falling through mid-air.
• Terminal Velocity Formula: V = √(2mg / pAC)
  • v = terminal velocity
  • m = mass of falling object
  • g = gravitational acceleration
  • p = density of fluid through which the object is falling
  • A = the projected area of the object
  • C = the drag coefficient
• The value of g varies slightly from place to place on Earth ≈ 9.8 ms⁻¹

Laws of Motion (Gravity)

• Gravity pulls all objects towards the earth at the same time naturally.
• Some light objects fall slower because of air resistance.
• All objects would fall together in a vacuum.
• Force, mass and acceleration are all relatable

Isaac Newton's 3 Laws of Motion

• Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed on it.
• Force equals the change in momentum per change in time; with constant mass, force equals mass times acceleration.
• For every action, there is an equal and opposite reaction.

Newton's Second Law

• Everything has inertia to change its state of motion or rest.
• An object will remain stationary or moving unless external forces act upon it.
• The second law Formula: Force = mass x acceleration (F=ma), or can be replaced by Weight = mass x gravitational strength (w=mg).
• The net result of every force is 0, due to an equal but opposite reaction.

Force and Weight

• Force/weight changes from Earth to the moon.
• Mass is constant while weight changes.
• Weight is 9.8 N on Earth where g = 9.8, but on the moon, Weight is 1.6 N where g = 1.6.

Friction

• When materials try to slide across each other, a force called friction stops them.
• Static represents the friction between objects that start to slide.
• Dynamic represents the friction during sliding.
• Fluid represents the friction caused when an object tries to slide inside a gas or a liquid.

Types of Motion

• Several types of motion exist:
  • Straight-line motion
  • Projectile motion
  • Centripetal motion

Centripetal Motion

• Circular motion produced by forces applied at right-angles.
• Centripetal Force Formula: mv²/r
  • r is the radius of the circle.
• Immediately after centripetal force stops, the object will travel straight on due to centrifugal force.

Gravity and Momentum

• The earth's gravity also causes satellites to travel in centripetal motion.
• To escape this, the object must reach escape velocity, which is 11,000 m/s.
• Momentum is an object's mass x velocity and is the quantity of motion in a moving body.
• Momentum Formula: mass x velocity.
• Force Formula: (mv - mu) / t v- final momentum u = the initial momentum.
• Force equals rate of change of momentum.

Rearranging Momentum Formula

• Ft = mv - mu (Impulse = Gain in momentum) Impulse represents the change in momentum.
• Momentum is conserved when two objects collide; their sum remains the same.
• (m₁xu₁) + (m₂ x u₂) = m₁v + m₂v where V is constant as the final velocity will remain the same.
• Confirms Newton's 2nd Law.
• Finding resultant forces between objects directly horizontal or vertical is simple addition/subtraction.

Resultant Force

• Resultant forces of angular forces are found by the Parallelogram rule.
• When two forces act on the same object, if the object is straight, it is a state of equilibrium, where clockwise and anti-clockwise moments are equal.
• A moment of force is a measure of the turning effect of the force about a particular point.
• Moment Force Formula: force x distance.
• For equilibrium, the sum of forces in one direction must equal those of the other direction plus the principle of moments must apply.
• Couples are long, parallel yet opposite forces.

Stability

• The moment amount of a couple represents torque.
• Considering the rules for equilibrium, there are different forms of stability, dependent upon these factors:
  • Center of gravity: Where the weight of an object pulls.
  • Center of mass: The mean position of the mass of an object.
• The three types of equilibrium:
  • Stable
  • Unstable
  • Neutral

Work (In Physics)

• Work must be done when a force produces movement.
• The SI unit for work is Joule.
• Work Forumla: W=fs Weight x Force = Distance.

Types of Energy

• To work, everything needs energy.
• Different types:
  • Thermal: Heat
  • Kinetic: Moving
  • Potential: stored
  • Electrical: Relating to current
  • Chemical: Relating to chemicals
• Kinetic energy is created when particles collide with one another, causing effective collision.
• This process can be sped by providing more heat to the particles and reducing their masses.

Energy Crisis

• Potential energy is the stored energy, found with this formula: Potential Energy = mgh.
• Energy that is created or destroyed, it only converts into other forms.
• After the work is done, the energy is subsequently transferred. -The energy crisis has taken a step forward in the whole world, for new methods that have to be made.
• Current methods release carbon dioxide which causes Climate Change

Power

• Power is the rate at which an energy source gets work done.
• Measured by this formula: Power = work done/time = energy transformed/time.
• Measured in watts (w).
• In motion examples: Power = force x velocity.
• The efficiency of an energy source is measured by this formula: Efficiency = power output/Power input.

Density

• In Physics, density refers to degree of compactness of a substance.
• Pure water has a density of 1.00.
• Density is given by: p = m/v m = mass v = volume.
• Fluid relative density equals density of substance/density of water.
• Relative density = mass of substance/mass of same volume of water.

Pressure

• Unlike pressure, density refers to the constant physical pressure applied on an object by something that is in contact with it..
• Measured in Pascals (Pa).
• Formula:Pressure = Force / Area.
• 1Nm⁻² = 1 Pa

Waves

• Waves are mediums of transferring energy without particles; disturbances propagating through space.
• Two types: Longitudinal waves (coils movehorizontally). Transverse waves (coils move vertically).
• Longitudinal wave; compression movement with rarefaction.

Transverse Wave

• The wavelength is the distance from one point to the same in the next oscillation λ
• The amplitude is the distance from the maximum/minimum point to the mean line.
• The time period of a wave is the time taken for an oscillation.
• The frequency (Hz) is the number of oscillations in one second.

Wave Formulas

• They are inversely proportional.
  • T = 1/f
  • f = 1/T

Phenomena of Waves

• Reflection is the bouncing off of a wave off a mirror-like substance.
• Specular reflection occurs when the mirror Surface is smooth.
• Angle of incidence = angle of refraction.
• Refraction is the bending of light due to varying speeds of light across different mediums.
• If the speed is faster, the ray will move away from the normal line.
• Index Formula: n = c/v light in air
  • n=sin Θ/sin Θ2.

Wave Interactions

• The critical angle is the angle at which, if light refracts, it becomes straight.
• There are two types of interference:
  • Constructive interference: crest on crest and trough on trough, causing a bigger wave.
  • Destructive interference: crest on trough and vice versa, causing a smaller wave or no wave at all.
• Diffraction bends waves as they more through a sli.

Characteristics of Sound

• Optimum level of diffraction occurs when slit's length is equal to the wavelength of the wave.
• A longer wave has lesser energy.
• About the speed/velocity of a wave: V=fλ.
  • V = λ/T time period
• Pitch distinguishes sounds between grave and shrill, being directly proportional to the frequency.
• Sound quality results when two sounds have same amplitude and frequency, but different patterns.
• Intensity measures sound energy transmitted per unit area, which is held perpendicular.
• Amplitude is directly proportional to energy; wavelength is inversely proportional to energy.

Concave Mirrors

• Loud sounds depend on 5 factors: Intensity. Amplitude. Surface Area of Vibrating body. Sensation of your ear Distance from vibrating body.
• The intensity of a wave Formula: Intensity = Power/Area.
• Waves can help in imaging.
• Two types of mirrors:
  • Concave Converges.
  • Convex Diverges.
• Captain Cold Valued Diamonds

Mirror Diagrams

• p = the object distance
• g = the image distance.
• f = the focal length
• Formula: 1/p + 1/q = 1/ftells of the Power of lens.
• Magnification Formula: q/p = Hi/H0

Mirrors

• The image type depends on the mirror and the distance.
• Electromagnetic Spectrum from high to low.
  • Radio
  • Microwave/Infrared
  • Visible
  • UV
  • X-ray
  • Gamma

Atomic Physics

• Study of radioactive elements and their isotopes.
• Protons and neutrons stick together due to binding forces, which with protons, neutrons, and electrons are made of finer particles called quarks.
• There are 6 flavors of quarks:
  • Up
  • Down
  • Top
  • Bottom
  • Charm
  • Strange
  • Radioactivity is the spontaneous disintegration of the nucleus of an atom with the emission of radioactive rays.

Types of Rays

• Include Alpha, Beta and Gamma.
• To show an element, A = Atomic Mass and Z = Atomic Number.
• An element is only radioactive if its atomic mass is greater than 82 amu.
• Three main types of radioactive rays:
  • Alpha (α)
  • Beta (β)
  • Gamma (γ). Alpha particles are helium nuclei (²₄α).
• They have no electrons and are positive.
• Penetration Power relates to how different rays pass through materials.
  • Alpha are low.
  • Beta are medium.
  • Gamma is high.
  • Speeds depend on the ray.
  • Gamma has the fastest speed.
  • Alpha has 10% the speed of light.

Radioactive Rays

• Beta particles are fast-moving electrons, and negative.
• Gamma rays have no charge, and are photons, or energy particles.
• Ionization power is the number of charge (+) a ray can provide to the medium it flows in.
• Alpha has a low ionization power: It is 2 electrons short from a full shell.
• Beta has a slightly higher (1) due to gaining one electron from traveled material.
• Gamma Rays have 20 because no charge Ionize.
• There are several uses of these radioactive rays.

Alpha Rays

• Are used to detect the amounts of nutrients in certain crops.
• Beta rays are used for investigating patients' bodies, tracing organs without surgery.
• Gamma sterilize equipment, killing cancer cells, detecting breakages and leakages in pipes.
• A Geiger counter determines if a radioactive ray is Alpha, Beta or Gamma.
• Alpha Decay is a radioactive isotope (an element with an unstable number of neutrons) and can decay to be stable.

Types pf Decay

• Alpha Decay formula: ²Aₓ → ⁴A₋₂Y + ²₄He
• Beta Decay (electron) formula: ²Aₓ → ²⁺¹AY + ₋₁⁰e
• Beta Decay (positron) formula: ²Aₓ → ²₋¹AY + ₁⁰e
• Gamma Decay occurs as protons get closer to neutrons, emitting a gamma ray.

Calculating Age

• Carbon Dating follows this principle and finds a substances age based on its emissions.
• Half-life measures during which the number of atoms in a substance reduces to half.
• Time taken for the number of atons to half = constant.

Nuclear Fission

• A nuclear plant works on the principle of fission, which is the process of a neutron being bombarded onto an atom.
• Two types of Nuclear Reactions:
  • Controlled (Nuclear Reactor).
  • Uncontrolled (Atomic Bomb).
• Example of a Nuclear Reaction: ¹²²U + ²¹n → ¹²²Ba + ᠎³⁶Kr + ²¹n

Fission Conversions

• E=mc² converts between mass and energy, where c is the speed of light.
• Uranium fuel is loaded into a reactor producing neutrons and splitting atoms.
• Control rods control the speed of the reaction.
• Water is pumped into this.
• Hot water passes through the heat exchanger, that moves it in turn towards the turbine.
• The turbine links to a generator to produce electricity, which is transported through power grids.

Nuclear Fusion

• Apart from Fission, Fusion is a power source too.
• Fusion is the process of two nuclei combining to create one large nucleus.
• Example: ²¹H + ²¹H → ⁴₂He + ⁰¹n
• Since the two isotopes are positive, they repel.
• A temperature of upTo to 150 million°C may be needed and Fisson can be used to carry this out.
• Fusion however has faults: high temperatures, high costs and uncontrollable reactions.

Thermodynamics

• Heat is a form of energy that flows from one body to another, specifically from high to low.
• The SI unit is Joules; which is measured via thermometer or calorimeter.
• The loss of heat in hot object equals the heat gained by thermal object to reach equilibrium.
• The units
  • Kelvin (K)
  • Celcius (C) / Centigrade
  • Fahrenheit (F).
• To convert between Kelvin and Celcius formulas is K = C +273
• To convert between Celcius and Fahrenheit = C=5/9(F-32)

Heat Capacity

• The amount of heat required to raise the temperature of 1 C or 1 k.
• Specific heat capacity of the measure to temp needed 1k - 1 kg substance. Specific heat capity = 4,184.

Heat

• formula Q = mc?
• The power of a body formula P=Q/T
• And P = mc?T/t.

State Changes

• Points B-C and D-E indicate that temperatures is constant when converting solid to liquid.
• Solid-liquid is melting.
• Liquid-gas is Boiling.
• Liquid-Solid is freezing.
• Gas-Liquid is Condensation.
• Solid- Gas is Sublimation.
• Gas-Solid is Solidification.

Graphs of Changes

• A-B: Gas in state (temp. falls)
• B-C: Phase change (condensation)
• C-D: Liquid in state (temp. falls)
• D-E: Phase change (freezing)
• E onwards: Solid in state (temp. falls).

Boiling vs Evaporation

• Differences between boiling and evaporation:

Electricity And Magnetism

• Charge is the tendency of electrons to attract other electrons.
• Belongs to an ion orcharged particle.
• Coulomb's Law: Force α q1,q2 The more force.
• More electrons.

Static Electricity

• Electricity is inverse to the R.
• F=x9192/R2 is the constant air.
• If Force increases charge increases too constant varies across different medin Paper is better.

More On Electricity

• Static Electricity has two objects rubbing against one another giving energy.
• Two Electrons have enough to escape object when electrons move back = neutral one A= positive one B= negative.
• Electrostatic induction the insulator and conductors have the same unlike sides.

Electrical Objects

• Electrostatic inducting is Electrics or fields. A Circuit has an enclosed which electrictly flows.
• The term of how negatives flow. Amp is measured in Amperes.
• Electrons flows throw the circuits carry enegy serve no purpose becomes unbalanced.

Types Of Circuits

• Series have only path electrical flow
• Parallel is multiple paths Series include bulbs, switch, better etc..

Circuit Electricity

• The Voltages changes across resistence = constant.
• Voltages = The energy that consumes or did.
• The charge electric potential the same find in v= B-A

Electrons

• Electron opposition tow Flow.
• Current electrons can not.

Electric Current

• Electric Potential.
• R/L using ohms.

Parallel Circuits

• To find electrical resistance you use
  • Rt= R2+R3.
• More power to calculate is watts P=V/1
• The tool to connect electrical resistence is a divider that provides resistance.

Electromotive Force.

• Measured in energy charge = No force.
• The resistance with the ability electricity "super conductors" no resistant what ever.
• The can be AC but are metal.

Electronics

• The ability electrons more freely to that.
• Refers the phenomena.
• " Electromagnetic" of fields is related to current
• Conducter with electromagnet can create.

Magnetism

• Induced magnetic flied cause conductive EMF of a magnetic conductor area change flux can induced.
• Faradays law a charge in flux.
• Flux affect the poles the number of affect the process.

Magents

• Lenz law.
• The electrical will oppose charges produce is.
• All be produced on electromagnetic high scales.

Parts of Alternating Generators

• Generator of the rotor.
• Mechanics and elcterials.

Generators

• They move and provide elctrisms and create
• DC DirectCurrent they stay the consistent where other change.

Electrical Transformers

• How Distructed Step ups.
• Low traveling down to houses.

Voltage

• Transformers are used to increase or descrease voltage Types are Low or High. High for transporting while Low is for Homes.

Astrophysics - the stars

• Studies or things the celestials or the solar etc.
• Bodies of comets stars and plantoids etc., with stars which can be burning and fuel their heat.
• They are large and provide fire.

Planets characteristics

• Orbits a star in oval path
• They nearly round
• The are any other plant moons
• Not have debirs around their orbirt

Worlds

• Can be 1024 number 2 types terrestrial and Jovians.
• Terrestrial is solid and rocky with molten core craters.
• Jovious are large molten mostly with hydro and atoms
• They make with the inner parts.
• Earth Mars

Planets

• All the planets are the same some are in their outer space.
• They collided due to gravity, the sun
• Satellites can be moons or orbiting stars.
• Satellites reflect the uplink back to earth.

Big Bang Theory.

• Data is processed, transfer and downlink occurs.
• Everything is 7 yrs after.

Galaxy Origins

• As everything expand the "dot" began to be made of 10 seconds to produce new quakes stars begin to have atoms form and galaxies can create.
• As travel happen that happen be what they are not creating.

Telescopes

• Telescopes assist with finding the universe.

• Used for photographing etc or comets .

• Types : Go To, Refractive, Refractive.

• Optical instruments can make things seem nearer and focus lines to see objects better.

• A telescope can collect lights to gather.

Solar Systems

• A star system
• Mercury, Venus, earth, Mars, asteroid, Jupiter, Saturn earth