Section A - Distance, Displacement, Velocity and Acceleration, Equation of Motion
1. REST AND MOTION :
* An object is said to be in motion wrt a frame of reference S1, when its location is changing with time in same frame of reference S1.
* Rest and motion are relative terms.
* Absolute rest and absolute motion have no meaning.
Motion is broadly classified into 3 categories.
1. Rectilinear and translatory motion.
2. Circular and rotatory motion.
3. Oscillatory and vibratory motion.
1.1 Rectilinear or 1-D Motion
When a particle is moving along a straight line, then its motion is a rectilinear motion.
Parameters of rectilinear motion or translatory motion or plane motion:
(A) Time :
* It is a scalar quantity and its SI unit is second(s).
* At a particular instant of time, a physical object can be present at one location only.
* Time can never decrease.
(B) Position or location - It is defined with respect to some reference point (origin) of given frame of reference.
Consider a particle which moves from location
(at time t1)
(at time t2) as shown in the figure below, following path ACB.