DYNAMICS – Lecture Notes / Mehmet Zor
- Kinetics is a sub-branch of dynamics where we make calculations by taking into account external forces that are the causes of movement. Our aim is to determine the velocity, acceleration, position or external forces at a time t.
- Our basic equation is Newton's 2nd law F=ma (Force = mass x acceleration).
- We use 3 different methods when solving problems:
- It should not be forgotten that; the 2nd and 3rd methods are actually different interpretations of the F=ma equation, that is, they are not independent methods. In fact, a kinetic problem can be solved with all 3 methods. However, if the method is preferred according to the situations mentioned above, the result is reached faster and more practically..
1st Method: Direct application of the equation F=ma with D’alembert’s Principle: In this method, solutions are made by directly taking into account the acceleration of the object. It is especially preferred in problems where external forces or acceleration are significant.
2nd Method: Work-Energy : It is a method where we solve without taking acceleration into account.
3th Method: Impulse_momentum: It is especially preferred in problems where external forces change over time or in collision problems. We can reach the result without having to take acceleration into account.
- Now we will examine these methods for particle kinetics in order and solve examples for each method..>>
General Information About Kinetic Calculations
- These 3 methods can be applied to particles, and will also be explained separately for rigid bodies in the 4th topic.