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GenPhysics q1 module Cheat Sheet (DRAFT) by

+Units and Measurement +Vectors +Kinematics +Laws of Motion +Work, Energy, and Energy Conservation +Center of Mass, Momentum, Impulse, and Collisions

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Module 1 - Measur­ement

Fundam­ent­al/Base Quantities - group of physical quantities that can be measured without relying on other quantities; (mass, length, molar mass, luminous intensity)
Derived Quanti­tites - use any combin­ation of fundam­ental quantities; (velocity, accele­ration, rate, force)
Convertion of Units - convertion between different units for the same quantity
Unit prefixes - placed before the symbol of a unit to specify the order of magnitude of the quantity; used for very large or very small numbers

Prefixes

Notations

Regular Notation
standard way of writing numbers
seven hundred sixty = 760
Scientific Notation
convenient and shorthand way of writing really large or really small numbers
280,00­0,000 = 2.8 × 108
   
0.000817 = 8.17 × 10-4

Module 2 - Accuracy and Precision

Signif­icant Figures - digits that carry meaningful contri­butions to its measur­ement resolu­tions
1. Non-zero digits are always signif­icant
2. Any zeroes between two signif­icant digits are signif­icant
3. A final zero or trailing zeroes in the decimal portion only are signif­icant
13000 = 2 sig. figs.
0.00410 = 5 sig. figs.
9.6010 × 108 = 5 sig. figs.

Accuracy - describes how close a measured value is to the true value, it is expressed using relative error:
Relative error = |(measured value - expected value)­/(e­xpected value)| × 100

Precision - degree of exactness with which a measur­ement is made and stated; for example, 1.324 is more precise than 1.3; it is expressed as a relative or fractional uncert­ainty
Relative Uncert­ainty = (uncer­tainty / measured quantity) × 100

Module 3 - Vector and Scalar Quantities

-Scalar quantities are described by a magnitude (size or numerical value) only; (Mass - amount of matter in your body = g or kg)
-Vector quantities give both the magnitude and direction; (Weight - amount of gravit­ational force exerted on the matter = kg⋅m/s2 or N)

Vectors and Addition of Vectors

Vectors - can be repres­ented by a ray line ; the length of the arrow represents the magnitude while the direction of the arrow represents the direction of the vector; the tail is called the initial point or the origin
Vector Direction - North, South, East, West; however, some vectors are projected to a certain degree: 30° North
Magnitude of a Vector - shown by the length of the arrow with a chosen scale
Resultant Vector - vector sum or difference of all individual vectors

Methods of Adding Vectors

Graphical
Analytical
choose approp­riate scale and frame of reference
Vectors in the same or opposite direction must be added with sign conven­tion; North and East (↑→) are positive and South and West (↓) are negative
use tools of measur­ement (basta may mineme­asure ka bes)
Vectors perpen­dicular or in right-­angle, use pythgorean theorem for magnitude and trigon­ometric functions for direction
 
Vectors not perpen­dic­ular, use law of cosine for magnitude and law of sine for direction
-Another way is the component method were the x and y components of the vectors are determined to find the resultant

Module 4 - Displa­cement and Velocity

Motion - can also be described through visual repres­ent­ations like graphs
Accele­ration - rate of change in velocity
Constant Accela­ration - when an object is moving with the same rate of change of velocity
Displa­cement - shortest distance from an object to the reference point; areas of velocity vs. time curve
Velocity - rate of change of position; areas of displa­cement vs. time curve
Average Velocity - total displa­cement of a body over a time interval
Instan­taneous Velocity - velocity at a specific instant in time

For more examples:

Module 5 - Accele­ration

Accele­ration - slope in velocity vs. time; if velocity is constant then there is no accele­ration
Instan­taneous Accele­ration - accele­ration at any instant time (only one point in time) (△v)/(△t)
Average Accele­ration - (total veloci­ty)­/(total elapsed time)

Slope of accele­ration

-Velocity (Y) is divided by Time (X) in a veloci­ty-time graph and positi­on-time graph
-To get the total accele­ration (only in veloci­ty-time graph), get the summation of all calculated accele­ration and divide it by the points in the graph (time periods); the unit will be m/s2

Module 6 - Uniformly Acc. Motion & Free-Fall

Uniformly Accele­rated Motion (UAM) - motion with constant accele­ration; velocity changes by equal amounts in equal intervals
Free-F­all­/Ve­rtical Motion - a uniformly accele­rated motion; objects in motion under gravity only (g = 9.8 m/s2)

UAM equations in one dimension

UAM equations in one dimension (free-­fall)

-the a is replaced by g, -9.8 m/s2 for downward accele­ration and vice versa

Module 7 - Components of Projectile

Projectile - any object that is thrown or otherwise projected into the air
Trajectory - charac­ter­istic path of a projec­tile; a parabola
Projectile Motion - describes the movement of a projectile along its trajectory

Module 8 - Time at Max Height of Trajectory

Half Time of Flight - time it takes for a projectile to reach the maximum height; t = √(2dᵧ/g)
(where dᵧ = (Vᵢᵧt)­/(½­gt²), t = time of flight, g = accele­ration due to gravity)

Total time of flight - double the half time of flight; t = (Vᶠᵧ - Vᵢᵧ)/g
(where Vᶠᵧ = final vertical velocity, Vᵢᵧ = initial vertical velocity, g = accele­ration due to gravity, t = time of travel)

Maximum Height - highest point the projectile can reach in the trajec­tory; the displa­cement formula is used: dᵧ = (Vᵢᵧt)­/(½gt²)
(where dᵧ = vertical displa­cement, Vᵢᵧ = initial vertical velocity, t = time of flight, g = accele­ration due to gravity)

Range of the Projectile - distance from the initial point on the ground to the final point it reaches; dₓ = Vᵢₓt
(where dₓ = range, Vᵢₓ = initial horizontal velocity, t = time of flight)

X and Y Component of the Velocity - used to determine the graph of trajec­tory; Vᵢₓ = Vᵢ cos θ and Vᵢᵧ = Vᵢ sin θ
(where Vᵢₓ = initial horizontal velocity, Vᵢᵧ = initial vertical velocity, Vᵢ = inital velocity, θ = angle of trajec­tory)

Module 9 - Circular Motion

Circular Motion - motion along a circular path in which the direction of the velocity is always changing; the speed is tangent to the path and the force towards the center is constant

Tangential Speed (vᵣ) - speed of an object in circular motion; depends on the distance from the object to the center. If the tangential speed is constant, the motion is said to be uniform circular motion

Centri­petal Accele­ration - accele­ration directed toward the center of the circular path; centri­petal accele­ration = (tange­ntial speed)­²/(­radius of circular path) or a꜀ = vₜ²/r

Tangential Accele­ration (aᵣ) - accele­ration of a certain object in a circular motion due to change in speed

Non-un­iform Circular Motion - an object moving in a circular path with changing velocity

Centri­petal Force - "­cen­ter­-se­eking force,­" net force directed toward the center of the circle; Fₙₑₜ = F꜀ₑₙₜᵣ­ᵢₚₑₜₐₗ
(where Fₙₑₜ = m×a; Fₙₑₜ = F꜀ₑₙₜᵣ­ᵢₚₑₜₐₗ = mass × centri­petal accele­ration)
F꜀ₑₙₜᵣ­ᵢₚₑₜₐₗ = mass × (tange­ntial speed² / radius of circular) OR F꜀ = mvₜ²/r
 

Module 10 - First Law Motion: Law of Inertia

Contact Forces - two objects having physical contact with each other (pushing or pulling)
+ Tension Force (t) - force transm­itted through a string, rope, cable, or wire, when it is pulled tight by forces avting on its opposite ends
+ Air Resistance - special type of frictional force that acts upon objects as they travel through the air
Normal Force (N) - support force exerted upon an object that is in contact upon another stable object
+ Friction (Ff) - force exerted by a surface as an object moves across it or makes an effort to move it across
+ Applied Force (Fa) - force applied to an object by a person or another object

Non-Co­ntact Forces - objects are subjected to a force but do not need to be in contact with each other
+ Gravit­ional Force - "Weight (W)"; the force with which the earth, moon, or other massively large object attracts another towards itself

Newton's First Law of Motion: Law of Inertia
-an object at rest stays at rest and an object in motion stays in motion with the same velocity unless acted upon by an unbalanced force
-valid for an inertial reference frame

Inertia - tendency of an object to resist changes in its motion; the heavier the mass, the greater is the inertia

Inertial Frame of Reference - frame of reference with constant velocity and non-ac­cel­era­ting;
For example, you are standing, and your speed relative to the ground is zero, but your speed relative to the sun is 2.97x104 m/s

Free Body Diagram - shows relative magnitude and direction of all forces acting upon an object; direction of arrow shows direction of force and the size of arrow shows the magnitude of force

Free Body Diagram

Module 11 - 2nd Law of Motion: Law of Accele­ration

-The accele­ration produced by a net force on an object is directly propor­tional to the magnitude of the net force, is in the same direction as the net force, and is inversely propor­tional to the mass of the object
-a is directly propor­tional to F where m is constant
-a is inversely propor­tional to 1/m where F is constant

accele­ration = (net force)­/(m­ass); a = F/m; F = ma

Weight - gravit­ational force exerted by a large body, measured in Newton (N); W = mg

Module 12 - 3rd Law of Motion: Law of Intera­ction

-when one object exerts a force (action) on a second object, the second object exerts a force (reaction) on the first object that is equal in magnitude but opposite in direction
F₁ = F₂ or force of action = force of reaction

Friction - force that opposes the motion between two surfaces that are in contact
Coeffi­cient of Friction - level of friction that different material exhibit; μ = Ff/N
(where μ = coeffi­cient of friction, Ff = friction, N = normal force)
Static Friction (fₛ) - acts on objects when they are resting on a surface
Sliding Friction or Kinetic Friction (fₖ) - force that acts between moving surfaces

Module 13 - Work

Work - amount of force applied on an object over a displa­cement;
W = F×d
SI unit of Joules (J)
If the force is at an angle to the displa­cement using dot product:
W = F x d x cos θ

Module 14 - Power

Power - measures rate at which work is done or energy is transf­ormed; P = (Work)­/(Time)
SI Unit: Joule per second (J/s)
if Force and Displa­cement were given: P = (Force­)(D­isp­lac­eme­nt)­/(Time)
if it's in an angle: P = (Force­)(D­isp­lac­eme­nt)­(cosine Ø)/(Time)
if Velocity is given: P = (Force­)(V­elo­city)
if it's in an angle: P = (Force­)(V­elo­cit­y)(­cosine Ø)

Module 15 - Energy and Energy Conser­vation

Energy - property of an object or system that enables it to do work; measured in Joules
Mechanical Energy - energy due to the position of something or the movement of something; sum of kinetic and potential energy and therefore always stay the same

+ Potential Energy - stored energy; form of energy due to the position of an object to the other objects or a reference point.
Gravit­ational Potential Energy - energy due to the object’s position relative to the gravit­ational source; depends on the height from a zero level
GPE = (mass)­(ac­cel­eration due to gravit­y)(­height) or GPE = mgh
Elastic Potential Energy - energy stored in a compressed or stretched spring or object
EPE = (½) (spring consta­nt)­(di­stance compressed or stretc­hed)² or EPE = ½kx²

+ Kinetic Energy - Work done to change the speed of an object; depends on mass and speed
KE = (½)(ma­ss)­(sp­eed)² or KE = ½mv²
Work-E­nergy Theorem - whenever work is done, energy changes; if work is done on an object, the net work is equal to its change in kinetic energy
Workₙₑₜ = change in kinetic energy or Workₙₑₜ = △KE or
Workₙₑₜ = ½mv²(f­inal) - ½mv²(i­nitial)

Module 16 - Center of Mass

-The formula for computing the velocity of the center of mass of a system in three dimensions may be obtained by replacing x, y, and z by vx, vy and vz, respec­tively.

Module 17 - Momentum and Impulse

Momentum - describes the difficulty in changing the state of motion of a moving object; p = mass×v­elocity
Impulse (I) - product of the force and the time it takes for the force to be applied; SI unit of kg.m/s
I = Force×time or I = m(vf - vi)
Impuls­e-M­omentum Theorem - since p = mv, I = △p

Module 18 - Conser­vation of Momentum

Law of Conser­vation of Momentum - the total momentum before the collision is equal to the momentum of the system after the collision; pf = pi
Coeffi­cient of Restit­ution (e) - negative ratio of the relative velocity of two colliding bodies after a collision to the relative velocity before the collision; e = (vₓ₂ - vᵧ₂)/(vₓ₁ - vᵧ₁)
(where vₓ₂ and vᵧ₂ =veloc­ities of bodies X and Y after collision, vₓ₁ and vᵧ₁ = velocities of bodies X and Y before collision)
The coeffi­cient of restit­ution can have a value from 0 to 1, depending on the type of collision

Elastic Collision - both momentum and kinetic energy are conserved; the coeffi­cient of restit­ution is equal to 1
Inelastic Collision - total momentum is conserved but the total kinetic energy is not conserved, some of the kinetic energy goes into other forms like heat, sound, and permanent deform­ation; the coeffi­cient of restit­ution for inelastic collision is between 0 to1
Perfectly Inelastic Collision - intera­cting bodies stick together and move as one after a collision; the coeffi­cient of restit­ution for inelastic is 0

YEY! you finished q1, I am so proud of you :)