Physical Science Reviewer

PROPERTY

A special quality or characteristics of something

PHYSICAL

Something that is real in the sense that it can be seen, felt, etc. and thus can be described

PHYSICAL PROPERTY

A describable quality of something observable

Example of Physical Property

• Length

• Mass

• Smell

• Temperature

• Color

• Conductivity

QUANTITY

An amount or a number of something

PHYSICAL

Something that is real in the sense that it can be seen, felt, etc. and thus can be described

PHYSICAL QUANTITY

A physical property that can be expressed in numbers.

PHYSICAL QUANTITY

A physical property that can be expressed in numbers.

Measurement

is simply a comparison of a physical quantity with the standard.

METRIC SYSTEM

meter, kilogram, second

ENGLISH SYSTEM

foot, pound, second

Le Systeme International d' Unites

is the modern form of Metric System.

International System of Units (SI)

It i s the system of units that the General Conference on Weights and Measures has agreed upon and is legally enforced in almost all parts of the world.

BASE QUANTITES

• There are seven base quantities

BASE QUANTITES

• Expressed in base units

DERIVED QUANTITIES

• These are combined base quantities

DERIVED QUANTITIES

• Expressed in combined base units

Example of Base Quantities and Units

• Length - meter (m)

• Time - second (s)

• Amount of substance - mole (mol)

• Electric current - ampere (A)

• Temperature - kelvin (K)

• Luminous intensity - candela (cd)

• Mass - kilogram (kg)

NEWTON

Isaac Newton

PASCAL

Blaise Pascal

JOULE

James Prescott Joule

WATT

James Watt

COULOMB

Charles-Augustin de Coulomb

VOLT

Alessandro Volta

Uncertainty of measurement

the doubt that exists about the result of any measurement.

RANDOM ERROR

The uncertainty (experimental error) that arises from a scale reading

Random error

indeterminate error, results from the effects of uncontrolled variables in the measurement. It is always present and cannot be corrected

systematic error, or determinate error.

Other uncertainties come from a flaw in the equipment used or the design of an experiment. It can be discovered and corrected

PRECISION

consistency of a result.

ACCURACY

determined when a certain quantitative value is relatively close to the "true" value.

SIGNIFICANT FIGURES

are the digits in any measurement that are known with certainty with an additional digit which is uncertain.

RULES FOR COUNTING SIGNIFICANT FIGURES

1. All nonzero digits are significant.

Example: 1.234 kg has four significant figures.

2. Zeroes between nonzero digits are significant.

Example: 40 507 cm has five significant figures.

3. Zeroes to the left of the first nonzero digit are not significant.

Example: 0.009 dm has one significant figure.

4. If a number is greater than one, all zeroes to the right of the decimal point are significant.

Example: 7.00 km has three significant figures.

5

If a number is less than one, only the zeroes at the end of the number and the zeroes between two nonzero digits are significant.

Example: 0.02010 g has four significant figures.

6. The zeroes immediately to the left of an unexpressed decimal point are not significant.

Example: 400 m has one significant figure.

SCIENTIFIC NOTATION

It is the process of simplifying a very large number or a very small number and is used to express multidigit numbers involving many zeros in compact form.

In addition and subtraction

the answer must have the same number of decimal places as the measured number with the least number of decimal places.

In multiplication and division

the answer must have the same number of significant figures as the one measured with the lowest number of significant figures.

Rounding off

is the process of removing insignificant digits from calculated numbers.

Motion

is always relative.

Motion

change in position of an object with respect to another object over time.

Kinematics

studies motion without delving into what caused the motion.

Aristotelian Motion

Natural motion, also called vertical motion

Aristotelian Motion

natural tendency of an object to go its natural place.

Aristotle

According to ______, it was natural for heavy things to fall and for very light materials to rise.

Thus, using the elements that made up the Earth, Earth's natural place is water, water below air, air below fire and all below aether.

violent motion

is the result of removing an object from its natural place.

Violent motion

literal interpretations of what was observed with the naked eye.

Galilean motion

its natural tendency was to continue to move without any assistance.

Galileo

According to him, the reason why the cart tended to slow down or stop was because of friction - a force that opposes the motion of an object.

Distance (d)

• how far you have traveled, regardless of direction.

Displacement (Ax)

• Displacement is the change in position (or location)

Displacement is a vector with both magnitude and direction

Speed

is the rate at which distance changes.

Speed

• Is a scalar quantity which tells the distance travelled within a given time interval.

AVERAGE SPEED

• Describes the total distance travelled within a given time interval.

Formula of Speed

Average Speed = total distance/total time

Speed

is a scalar (how fast something is moving regardless of its direction).

Speed

is the magnitude of velocity.

Velocity

is a combination of speed and direction.

VELOCITY

Is a vector quantity that describes the change in displacement with respect to change in time.

AVERAGE VELOCITY

• Describes the change in displacement within a given time interval.

Uniform motion

moving with constant velocity

Uniform motion

velocity remains constant and has zero acceleration

Distance vs Time Graph

the relationship between the distances covered by the object over a period of time.

velocity of the object

the steepness or slope of the graph represents the ________.

Velocity vs Time Graph

is just a straight horizontal line

Acceleration vs Time Graph

its acceleration is equal to zero, Thus, the graph has no line or dot on it.

Acceleration

The rate at which an object changes its velocity

ACCELERATION

- how fast you speed up, slow down, or change direction; it's the rate at which velocity changes.

Velocity (+); Acceleration (+)

Moving forward; speeding up

Velocity (-); Acceleration (+)

Moving backward; slowing down

Velocity (+); Acceleration (-)

Moving forward; slowing down

Velocity (-); Acceleration (-)

Moving backward, speeding up

Isaac Newton 1642-1727

Who proposed Newton's Law of Motion?

Galileo

Who prompted Sir Isaac Newton to develop the three Laws of motion which explain why things behave the way they do?

Galileo

Who concluded from his experiments that objects in motion tent to maintain their state of motion while an object that is originally at rest will remain at rest.

Inertia

He called this tendency of an object to maintain its initial state

Law of Inertia

Every body persists in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by force impressed.

Law of inertia

An object at rest tends to stay at rest, an object in motion tends to stay in uniform motion unless acted upon by some external net force

Law of Inertia

• More mass=more inertia

Mass

• is a measurement of an object's inertia whether at rest or in motion.

Inertia of Rest

The inability of a body to change by itself its state of rest

Inertia of Rest

Person sitting in a car falls backwards, when the car suddenly starts,. It is because the lower portion in contact with the car comes in motion where as the upper part tries to remain at rest due to inertia of rest.

Inertia of Motion

• Inability of a body to change by itself its state of uniform motion

Inertia of Motion

• When a moving car suddenly stops, the person sitting in the car falls forward because the lower portion of the body in contact with the car comes to rest whereas the upper part tends to remain in motion due to inertia of motion.

Inertia of Direction

• When a car moves round a curve the person sitting inside is thrown outwards in order to maintain his direction of motion due to inertia of motion.

Inertia of Direction

• The inability of a body to change by itself its direction of motion

Force

• is an interaction between two objects or between an object and its environment.

•  is a vector quantity, with magnitude and direction.

Normal force

• When an object pushes on a surface, the surface pushes back on the object perpendicular to the surface.

• Contact force

Friction force

• This force occurs when a surface resists sliding of an object and is parallel to the surface.

Tension force

A pulling force exerted on an object by a rope or cord.

Weight force

The pull of gravity on an object. This is a long-range force (a force that acts over a distance).

Net Force

• Sum of the vectors representing these multiple forces operating on an object

Net force is not zero

• there will be some acceleration, meaning there is motion.

Net force is zero

• there will be no acceleration (no motion).

Law of Acceleration

the acceleration of an object is directly proportional to the net force and inversely proportional to mass

Law of Interaction

"for every

action, there is an equal and opposite reaction".

Law of Interaction

The baseball forces the bat to the left; the bat forces the ball to the right.