NCERT Based Notes by an NITian

3. MOTION IN A STRAIGHT LINE 3.1 INTRODUCTION Kinematics: A branch of physics that deals with the motion of an object without going into the cause of motion is known as kinematics. Motion: The change in the position of an object with time with respect to a reference is called motion. Rectilinear motion: The motion of an object along a straight line is called rectilinear motion. Point object: The object whose size is much smaller than the distance it moves in a resonable duration of time are considered to be a point object. 3.2 POSITION, PATH LENGTH AND DISPLACEMENT Reference point : An arbitrary point taken as origin serves as the reference point. Frame of reference : The coordinate system along with a clock is called a frame of reference . ➤ If one or more coordinates of an object change with time, the object is said to be in motion. Otherwise the object is said to be in rest with respect to this frame ...