Science is a systematized body of knowledge based on facts. It is a study of life and non-life. It is a never-ending quest and the greatest creation of God.

Science

Natural Science Social Science Applied Science

Physical Science Biological Science

Physics, Chemistry, Meteorology, Astronomy, Geology, Oceanography

Physics is the scientific study of matter and energy. It deals with the fundamental concepts like time, motion, forces, space, matter, energy, gravity, and radiation.

I. Measurement is the process of comparing an unknown quantity with a known or fixed quantity called standard.

Fundamental Quantities ~ measurement chosen arbitrarily and independently of the scales of other quantities.

7 Fundamental Units

meter (m) – distancekilogram (kg) – masssecond (s) – timeampere (A) – electric currentKelvin (K) – temperaturemole (mol) – amount of substancecandela (cd) – intensity of light

Derived Quantities ~ obtained by multiplying or dividing the fundamental units

System of Units

1. English System of Units ~ developed by the English-speaking countries of the world.

Common units:Inch, foot, yard, mile, rod (16 ½ ),

furlong(660 ft)

2. Metric System~ proposed in 1971 by the French National Assembly

Common Units:Meter (length), gram (mass), liter

(volume)

3. International System of Units (SI) ~ established by the Treaty of the Meter (1875)

Prefixes Symbol Equivalent

mega M 106

kilo k 103

hecto h 102

deka da 10

deci d 10-1

centi c 10-2

milli m 10-3

micro μ 10-6

nano n 10-9

Pico p 10-12

Length

Defined as the interval or distance between two points

“How long?”, “How far?”, “How high?”

Mass The amount of matter in an

object

WeightThe measure of force exerted by

Earth on an object

Time

The interval between two events at the same place in space.

TemperatureThe measure of the average kinetic

energy in molecules or atoms of substance.

Conversion of Units/Dimensional Analysis*The key to using dimensional analysis is the correct use of conversion factors to change one unit into another. A conversion factor is a fraction whose numerator and denominator are the same quantity expressed in different units.

e.g.

2.54 cm and 1 in are the same length, 2.54 cm=1 in. This relationship allows us to write two conversion factors:

2.54 cm and 1 in

1in 2.54 cm

Thus the length in cm of an object that is 8.50 in long is given by:

Number of cm= (8.50 in) 2.54 cm = 21.6 cm

1in

Given Unit

Desired Unit

To multiply a quantity by a conversion factor, the units multiply and divide as follows:

Given unit X desired unit = desired unit

given unit

If a woman has a mass of 115 lb, what is her mass in grams?

1 lb= 453.6 gMass in grams = 115lb (453.5)=5.22 x 104 g

(1 lb)

10 m = ____________ km2km = ____________ cm250 mL = ___________ L1500 cc = ___________ L

Significant Figures

1. Any digit that is not zero is significant. e.g. 226.28 - __________

14344.21 – ________2. Zeros between non-zeros are significant.

e.g. 1002.5 - _________3. Zeros to the left of the first non-zero digit

are not significant.e.g. 000 226 – _______

0.002 8 - ________4. If the number is equal to or greater than

one (1), then all zeros to the right of the decimal point are significant.e.g. 457.10 - _________

400.00 - _________

5. If the number is less than one, then only zeros that are at the end of the number and between non-zero digits are significant.e.g. 0.01020 - ________

0.060 - ________6. For the numbers that do not contain

decimal points, the trailing zeros may or may not be significant.e.g. 3 000 000 - __________

3 000 000 - __________

Operations on Significant Figures

1. Addition and Subtraction The number of significant

figures to the right of the decimal point in the final sum or difference is determined by the lowest number of significant figures to the right of the decimal point in any of the original numbers.

2. Multiplication and Division

The number of significant figures in the final product or quotient is determined by the original number that has the smallest number of significant figures.

Accuracy

and

Precision

Accuracy is how close a measurement is to the actual(accepted) value.

Example: Your watch

is accurate if it is

close to the time

kept by the National

Institute of Standards

and Technology

(N.I.S.T.)

Precision is how close a set of measurements are to each other.

Example: A field goal kicker is precise if he kicks the ball through the goal posts every time.

Scientific Notation

- also sometimes known as exponential notation, is a way of writing numbers that accommodates values too large or small to be conveniently written in standard decimal notation.

General Form:

M x 10n

where N = is a number equal to or greater than 1 but

less than 10n = is a positive or a negative integer

Express the following into scientific notation of 3 SF:

1. 145 000 = 2. 9 562 157 = 3. 0.000 075 =

Operations on Scientific Notation

MULTIPLICATION of exponentially notated numbers.

General format:

(Nx10x) (Mx10y) = (N)(M) x 10x+y

e.g. (3 x 104) (1 x 102) =

DIVISION of exponentially notated numbers.

General format:

(N x 10x) / (M x 10y) = N/M x 10x-y

e.g. (6 x 105)/(2 x 102) = ________

ADDITION and SUBTRACTION

General format:

(N x 10x) + (M x 10x) = (N+M) x 10x

(N x 10x) - (M x 10x) = (N-M) x 10x

e.g. (2.3 x 10-2) + (3.1 x 10-3) = ________

(2.3 x 10-2) - (3.1 x 10-3) = ________

II. Motion and Force

Mechanics~ the scientific study of motion

Motion~ a change in position with respect to a reference point/frame of reference

Mechanics

Kinematics Dynamics

Description of how objects move

Relation of motion to its cause

which is force

Kinematics

Distance and Displacement

Distance (d) ~ linear dimension between two points measured along the actual path

Displacement (d)~ a straight line distance from the starting to the end point and expressed with direction

Speed and Velocity

Speed~ the ratio of the distance traveled with respect to time.

v = d / tWhere

v is speed

d is distance

t is time

Velocity is the actual speed stated with direction.

a. A ball rolling at 5m/s forwardb. A car traveling at 60 km/h eastc. Typhoon Frank moving at 15

km/h west northwest

V = d / t

Where

v is velocity

d is displacement

t is time

1. A ball is rolling on the floor. It covers 15 m in 10.0 s. what is its speed as it moves?

2. A kangaroo is hopping at a speed of 15 m/s. How far would it be in 3.0 s?

3. What is the velocity of a police car that moves 450 m E in 25 seconds?

Acceleration is the rate of change of velocity. An object may accelerate if;

a. It increases or decreases its as it moves along the same direction,

b. It changes its direction as it moves with the same speed, or

c. It changes both its speed and direction.

a= vf - vi

t

Where a is acceleration

vf is final velocity

vi is initial velocity, and

t is time

1. A ball is initially at rest on top of an inclined plane. It rolls downward and hits the bottom of the inclined plane after 3.0 s with a speed of 1.5 m/s. What is the acceleration of the ball as it rolls?

2. A car is initially moving at 5.0 m/s. it is accelerating uniformly by 2.0 m/s2. how fast will it be moving after 10.0 s?

Dynamics

Force is commonly known as any kind of push or pull on an object.

Newton’s Laws of Motion

Law of Inertia:

An object at rest remains at rest and an object in motion will remain in motion at a constant velocity unless an unbalanced force acts on it.

Law of Acceleration:

Force equals mass X acceleration

When a net force acts on an object with mass m, the object accelerates with the acceleration given by

F = m a

Law of Interaction:

For every action, there is an equal and opposite reaction.

“Every force must have an equal and opposite force”

Uniform Circular Motion

A body moving at constant speed in circular path is accelerating because the direction of its velocity is constantly changing. The direction of this acceleration is toward the center of the path and its magnitude is given by

a = v2

R

Friction

In general when two objects are in contact there are two possible forces acting between them. The force perpendicular to the surface of contact we call the normal force and the force parallel to the surface of contact is called friction.

Laws of Planetary Motion

1. Each planet moves in an elliptical orbit, with the Sun at one focus of the ellipse.

2. A line from the Sun to a given point sweeps out areas in equal times.

3. The periods of the planets are proportional to the 3/2 powers of the major axis lengths of their orbits.

Law of Universal Gravitation

Newton’s Law of Gravitation states that two particles with masses m1 and m2, a distance r apart, attract each other with forces of magnitude

Fg = G m1m2

r2

Four Fundamental Forces 1. Strong Nuclear force is the strongest

and the reason for the binding of protons and neutrons to form a nucleus.

2. Electromagnetic force is responsible for binding electrons to nucleus forming atoms as a result.

3. Weak nuclear force governs radioactive decay of atomic nuclei.

4. Gravitational force is the weakest but its effect is felt on a large scale.

Fundamental

Force

Relative strength

Action distance

Strong nuclear 1 Short range

(10-15 m)

Electromagnetic 10-3 Infinite

Weak nuclear 10-8 Extremely short range (10-17 m)

Gravitational 10-45 Infinite

III. Work, Energy and Power

Work is what is accomplished when force moves through a distance.

Specifically, work done on an object is defined as the product of the magnitude of the displacement and the component of the force parallel to its displacement.

W= Fd

3 conditions that had to be considered in order to say that work is done:

1. There must be a force applied.

2. There must be a displacement.

3. There must be component of the force along the direction of displacement.

Is there a work done?

1. A boy lifts a chair upward.2. A boy pushes a table forward and

the table moves.3. A mother pushes a grocery cart at

30° with respect to the ground.4. A person pushing against the wall,

the wall remains stationary.5. A porter carrying a sack of rice on

his shoulder walks 50 m forward.

Practice exercises:

1. Coming from school, Elmer pushes the door of their house by a force of 50N. The door moves forward by 0.5 m. How much work did Elmer do?

2. John lifts a 10.0 N box to a height of 5 m from the ground. In the same way, Jean lifts 8.0 N box to a height of 2.6 m. Who does more work?

Power

The rate at which work is done.

In equation form,

P = W / t

The SI unit of power is watt (W).

Sample problem:

1. A firefighter weighs 700 N. He climbs a flight of stairs 7.0 m high in 17 s. How much work did the firefighter accomplished? What is his power rating in doing the work?

Different Forms of Energy

1. Potential Energy- stored energy

a.Chemical potential energy

b.Electrical potential energy

c. Elastic potential energy

d.Magnetic potential energy

e.Gravitational potential energy

Gravitational potential energy

GPE = mass x acceleration due to gravity x height

GPE = m x g x h

2. Kinetic EnergyEnergy carried by objects in

motion.

KE = ½ mv2

3. Thermal Energy

The total kinetic and potential energy of the molecules of an object.

4. Chemical Energy

5. Mechanical Energy

6. Light Energy

7. Electrical Energy

8. Sound Energy

Law of Conservation of Energy

Energy is conserved; can neither be created nor destroyed. It can only be transformed from one form to another.