Physics 1 Prelims

physics

study of matter and energy

explains natural phenomena in the universe

most fundamental science

based on experimental observations and quantitative experiments

math

language of physics

Classical Physics

before the 1900s

Isaac Newton (flagbearer)

the basics/fundamentals of physics were discovered here

MODERN PHYSICS

near the end of the 19th century until today

Albert Einstein (flagbearer)

Physical Quantity

any property that is used to describe a physical phenomenon

Units

describe the quantity being measured

f = 30N

f - physical quantity

30 - magnitude

N - unit

STANDARD UNIT OF MEASUREMENTS

length, mass, time

length

measures distance and space

mass

measures amt of matter an object contains (diff from weight: force exerted by gravity on the mass)

time

measure of the flow of events

DERIVED PHYSICAL QUANTITIES

other physical quantities can be constructed from these three and are called derived quantities

called derived units

Ex: m/s (velocity), force (kg * m/s²)

7 base units

• Quantity - Unit

Length - meter (m)

Mass - kilogram (kg)

Time - second (s)

Temperature - Kelvin (K)

Electric Current - Ampere (A)

Luminous Intensity - candela

Amount of Substance - mole (mol)

SYSTEM OF MEASUREMENTS

SYSTEME INTERNATIONAL (SI)

GAUSSIAN SYSTEM

U.S. CUSTOMARY SYSTEM/ENGLISH SYSTEM

SYSTEME INTERNATIONAL (SI)

aka International System of Units

standard system of units for the fundamental quantities of science

A.K.A. mks (meter, kilometer, second)

GAUSSIAN SYSTEM

A.K.A. CGS system (centimeter, gram, second)

U.S. CUSTOMARY SYSTEM/ENGLISH SYSTEM

A.K.A. English System

foot, slug, second

UNIT CONVERSION

multiple-step process that involves multiplication and/or division by a numerical factor, selection of the correct number of significant digits, and rounding

Units can be treated as algebraic equations that cancel each other

CARTESIAN PLANE

most commonly used coordinate system

made by Rene Descartes (1596 - 1650) in the 17th century

PYTHAGOREAN THEOREM

an important relationship between the lengths of the sides of a right triangle

x represents the horizontal axis

y represents the vertical axis

scalar quantities

quantities with magnitude only

ex: mass, temp, volume

vector quantities

quantities w/ both magnitude and direction

ex: weight (direction is almost always going down), velocity, force

terminal point

head tip of a drawn vector

length of a drawn vector

represents magnitude

tail of a drawn vector

initial point

addition of vectors

when 2 or more vectors are added, they must all have the same units

vectors can be added geometrically (by graphing) or analytically (using the component method)

commutative law of addition

when 2 vectors’re added, their sum is independent of the order of the addition (order of addition doesn’t matter)

REMEMBER:

always keep in ming what quadrant of the cartesian plane you are in

the value with cos always touches a specific axis

mind your signs

familiarize yourself with the multiples of 10

mind your units

mechanics

study of motion of objects

divided into 2 (Kinematics, dynamics)

Kinematics

deals with the quantitative description of motion

part of dynamics that describes motion without regard to its causes

Dynamics

focuses on the causes of motion

study of motion and of physical concepts such as force and mass

Motion

activity or process of continually changing position or moving from one place to another

Displacement

change in position (vector quantity)

Distance

magnitude of the displacement (scalar quantity)

frame of reference

choice of coordinate axes that defines the starting point for measuring any quantity

Average Acceleration

object’s velocity and acceleration - same direction → object’s speed increases w/ time

object’s velocity and acceleration - opposite direction → object’s speed decreases w/ time

Deceleration

reduction in speed, a slowing down

an object moves with constant acceleration

instantaneous acceleration at any point in a time interval = value of the average acceleration over the entire time interval.

velocity increases or decreases at the same rate throughout the motion

air resistance is negligible

all objects dropped under gravity’s influence near Earth’s surface fall toward Earth with the same acceleration

freely falling object

object moving freely under the influence of gravity alone, regardless of its initial motion

maximum height

object’s velocity when moving upward = 0m/s