MOTION IN A STRAIGHT LINE, Class-11

 

Motion in a straight line

1. Mechanics

   It is the branch of physics that deals with the conditions of rest or motion of the material objects around us.
   Sub- branches of mechanics :-
   (i)Statics:-It is the branch of mechanics that deals with the study of objects at rest or in equilibrium.
   (ii)Kinematics :- It is the branch of mechanics that deals with the study of motion of objects without considering the cause of motion.
   (iii)Dynamics:-It is the branch of mechanics that deals with the study of motion of objects taking into consideration the cause of their motion.

2. Rest[ state of rest ]

   An object is at rest if it does not change its position with respect to its surroundings with the passage of time.

3. Motion [state of motion ]

   An object is in motion if it changes its position with respect to its surroundings with the passage of time.
   Rest and Motion are relative terms. Nobody can exist in a state of absolute rest or of absolute motion.

4. Point object

   If the position of an object changes by distances much greater than its own size in a reasonable duration of time, then the object may be regarded as a point object.

5. One dimensional motion

   The motion of an object is said to be one dimensional motion if only one out of the three coordinates specifying the position of the object changes with time.
   In such a motion, an object moves along a straight line path.