Kinematics

 

Kinematics is the branch of classical mechanics that describes the motion of bodies (objects) and systems (groups of objects) without consideration of the forces that cause the motion.

When we study the motion of a body, we always have to do it respect to a Reference System, which is a point or set of points through which we describe the movement that a body has.
We say that a body is moving respect to a Reference System when it changes its position over the time, if it doesn’t change, we will say that it is in repose. The movement is relative, that is, it will depend on the reference system we choose.
If we join all the points where passes a body, we obtain a curve called trajectory, on which we can determine the position of a point that after join it with OX and OY axes, we obtain as result a vector called position vector.

The length or module of that position vector is calculated by:

 

FORMULA SUMMARY:

 

Scalar average velocity

 

Scalar instant velocity

 

Vectorial average velocity

 

Vectorial instant velocity

 

Average acceleration

 

Instant acceleration

 

Tangential acceleration

 

Normal acceleration

 

Rectilinear uniform motion

 

Rectilinear uniformly varied motion

 

Free fall motion

 

Angular magnitudes

 

Angular velocity

 

Angular acceleration

 

Uniform circular motion (T = period ; f = frequency)

 

Uniform circular varied motion

 

Vibratory harmonic motion (s = elongation ; A = amplitude ; ω = pulsation)

 

COMPOSITION OF MOVEMENTS

 

Vertical launch of projectiles

 

Horizontal launch of projectiles

 

Oblique launch of projectiles
 

Trajectory equation

 

Maximum Height

 

Final scope

 

 

 

 

You can download the App BioProfe READER to practice this theory with self-corrected exercises.