So up until this point, we were busy mostly with kinematics, that is things that involve the position,
the speed and acceleration of a particle.
But we considered this particle to be massless.
We did not consider the forces that might work in on this particle and that is called kinematics.
What are we going to look at going forward is kinetics and kinetics looks at the causes of motion that
will say that the particle that undergoes position, speed and acceleration has a certain mass which
we are going to consider.
We are going to consider certain forces that works on this mass and that is called also dynamics.
And an example of kinematics that we have looked at in the previous videos is the study of celestial
bodies, how planets move around the sun, for instance, how a moon moves around the planet.
You can describe the motion of that body using kinematics without considering the fact that the body
has a certain mass.
So Chromatics is just describing the position mostly as a function of time.
When you look at kinetics, you are going to incorporate the mass in the forces.
So that is mostly employed where you design things like airplanes and motor vehicles, trains, etc.
So they we need to consider how different forces work in on this body and for that we will use a free
body diagram.
So there are three methods of solving kinetics problems that we are going to look at.
The first one is Newton's second law, which says that F is equal to M times A, the force is equal
to the mass of the body multiplied by its acceleration.
And that force you will see is the sum of forces working on the body broken down into different directions,
you'll see.
We'll do an example of that.
So if is equal to M times a mass multiplied by acceleration, that's Newton's second law.
That is a starting point for solving some kinetics problems.
Another starting point for solving some kinetic problems is the principle of work and energy.
We will look at that as well.
And then we will also look at the principle of impulse and momentum.
So without further ado, let us look at Newton's second law and how we can use that to solve a kinetic
problem.