SUN

The sun is the center of the solar system. The sun is the largest object in solar system. It is diameter ia approximately 1,4 million kilometer it consists of hydrogent and helium. The sun is 333.000 times as massive as t

workshop

physics lessons for elementary schools, middle schools, high schools

Global Warming

Some plants are often grown in a glasshouse (greenhouse)What is advantage of a greehouse ?

extreme weather in Indonesia

frequent extreme weather in Indonesia, according to climatology meteorology and geophysics, extreme weather

greetings in Happy New Year 2012

Fisika Education : Teaching materials, practice questions and articles Physics for elementary, junior high school, vocational school

Sunday, July 15, 2012

Fundamental Quantities

Something can be measure and expressed by a value is called quantity, and generally it a unit.

A quantity use in science and tecnologi is a call a phisicall quantity.
Examples of physical quantities length, weight and time.


Ekample :
1.What quantity is being measure by this boy ?


2.What quantity is being measure by this man?


3.What quantity is being measure by this woman ?

4.What quantity is being measure by this man ?


The seven of fundamental unit of the International System
Fundamental Quantitiesunitabbreviationdimension
Length
meter
m
L
Mass
kilogram
kg
M
Time
second
s
T
Temperature
kelvin
K
θ
Amount of substance
mol
mol
N
Luminous intensity
candela
cd
J
Electric current
ampere
A
I


Very large or very small numbers are difficult to express such as the earth’s radius or time between collisions in SI units.
So to make it simple, we use a prefix.
prefix
abbreviatin
factor
exa
E
1018
peta
P
1016
tera
T
1012
giga
G
109
mega
M
106
kilo
k
103
hekto
h
102
deka
da
10

Wednesday, July 11, 2012

Particles Motion Kinematics

To reach the orbit, an instrument in the flight control room always monitors the position of the shuttle space an calculates velocity and the acceleration from a given position.

  1. Position

Position is the location of a particle relative to a frame of reference and expressed by the vector quantity r.
In a Cartesian coordinate, we use unit vector perpendicular to each other :
Unit vector i ( in x direction)  and unit vector j ( in y direction).
If the particle or object is at point (x,y), then is position expressed as
r = xi + yj

    r = 5 i+ 5 j

Displacement

2. Displacement is the change in position of partikel expressed as a vector quantity Δr
If r0 is the initial position and rt is the final position, then the displacement can be written mathematically as

r0 + Δr = rt 
Δr = rt – r0

Or

Δr = Δxi + Δyj






  1. Distance
Distance is the magnitude of displacement traveled by particle a scalar quantity  r| or Δr
Distance can bd write mathematically using Phytagoras theorem.

Δr =      


And the direction of the dicplacement θ is

tg θ =

Example



Δr =      
Δr =      
Δr =      
Δr =      
Δr =  5     

tg θ =  =  = 0, 75

θ = 300



learning physics in physics education site, may be useful

Related Posts Plugin for WordPress, Blogger...