Differences between these four branches of physics

Question

1. I am wondering what are the main differences between these four branches of physics: Statics, Kinematics, Dynamics, and Kinetics?

2. And whether the following relationships are correct or not?

   • Statics: there is no speed and there is no acceleration
   • Kinematics: there is speed and there is no acceleration
   • Dynamics: there is speed and there is acceleration
   • Kinetics: there is speed and there is acceleration

Answer 1

A simple Google search helps out. See this Wikipedia article and its menu in the right side. This questions is all about definitions of words:

• Statics: When the object is not accelerating and moving with (standing still on / in equilibrium with) its surroundings. The requirements are Newton's 1st law:

$$\sum \vec F=0 \qquad \sum\vec\tau=0$$

• Kinematics: The study of motion.

• Dynamics and kinetics: The study of the causes of (changes in) motion. That would be forces and torques etc. Newton's 2nd law tells the connection: $$\sum \vec F=m\vec a\qquad \sum \vec \tau=m\vec \alpha$$ The word dynamics took over more and more over the past 100 years, but as far as I'm aware the two words are used interchangeably depending on the field of science.