Motion

Motion
If a body changes its position with respect to its surrounding it is said to be in motion


Rest 
If a body does not changes its position with respect to its surrounding it is said to be in rest .


Reference Point
The point about which we study the motion of an object is called reference point.


Uniform Motion
If a body travels equal distance in equal interval of time, the body is said to be in uniform motion

Non-Uniform Motion

If a doesnot body travels equal distance in equal interval of time, the body is said to be in non- uniform motion.

Speed
The rate of change of distance per unit time is called speed. 
Speed=Distance travelled
              Time taken 
           = m     
               s    
           = m/s
Therefore, SI Unit of speed is m/s

Velocity

The rate of change of displacement per unit time is called speed. 

Velocity=Dislacement

                 Time taken 

              = m     

                  s    

              = m/s

Therefore, SI Unit of velocity is m/s

Distance Travelled
The length of a path travelled by a moving body in any direction is said to be in distance travelled.Its is a scalar quantity and it has magnitude (having unit) but no direction.It is measured in meter(m) in SI Units.


Displacement
The shortest distance between two points is called displacement.It iis a vector quantity.In SI System Unit of displacement is meter(m).The shortest is always the straight line.  

Difference between mass and weight

Difference between mass and weight

Mass	Weight
The amount of matter contained in a body is called mass.	The force of attraction exerted by Earth to pull an object towards its center is called weight.
It is constant.	It varies from place to place.
It is measured in beam balance.	It is measured in spring balance.

Important definination and notes

Time
It is defined as the interval between the  two events.
The SI Unit of time is Second. 

Mean Solar Day
The time taken by Earth to rotate around its axis is called 1 Mean Solar Day.
1 Mean Solar Day = 24 hr 
                              = 24 x 3600 s
                              =  86400 s.

1 Second

It is defined  as 1/86400 of a mean solar day.
1  minute =60 second (sec)

1  hour   =3600 second (sec)

Length
The distance between two points (ends) is known as length. Its SI Unit Is Meter.

Volume
The space occupied by a body is called volume. Its SI Unit is Cubic Meter (m³).  
Note *

Volume of a regular shape is calculated by using their respective formula i.e.  V= LXBXH

Volume of a irregular body is measured by displacement method. 
                                                                                                                      
Area
The total space covered by a body is called area. Its SI Unit is square meter (m²).
Note *
Area of a regular body is found by using their respective formula i.e. A = LXB 

Area of a irregular body is formed by plotting in a graph

Multiples and sub-multiples of

METER
mm   cm   deci    m    deca   hm    km


1 Meter           = 10 decimeters (dm)
1 Meter           = 100 centimeters (cm)
1 Meter           = 1000 millimeters (mm)
10 Meter         = 1 decameter (dm)
10 decameter  = 1 hectometer (hm)
10 hectometer = 1 kilometer (km)

KILOGRAM

mg   mm  deci   g  deca   hg  kg

1 Tonne      = 1000 kilograms (kg)

1 Quintal    = 100   kilograms (kg)

1 kilogram  = 1000  grams (g)

1 gram        =  1000 milligram (mg)

System

SI SYSTEM

It is known as Standard International System of Units which is the improved and extended Version  of MKS SYSTEM.


SYSTEM OF UNITS


CGS SYSTEM [FRENCH System of Measurement]
Length= Centimeter (cm)
Mass   = Gram (g)
Time    = Second (s)


FPS SYSTEM [BRITISH System of Measurement]

Length= Foot 

Mass   = Pound 

Time    = Second (s)

MKS SYSTEM [METRIC System]

Length= Meter (m)

Mass   = Kilogram (kg)

Time    = Second (s)