1 of 2

PLANAR KINETICS

OF RIGID BODY

DYNAMICS – Lecture Notes / Mehmet Zor

1

23 Agust, 2024

4.

(Causes of Motion in Mechanisms)

At the end of the chapter, in section 4.3, there are Exam Questions with Answers related to all chapter topics.

2 of 2

DYNAMICS – Lecture Notes / Mehmet Zor

2

23 Agust, 2024

Our aim in this section is

  • to determine the angular velocity, angular acceleration of rigid body at a time t, or
  • the velocity, acceleration, position of any point, or
  • unknown external loads,

taking into account external forces that are the causes of motion in rigid objects, and to reinforce the topics with sample problems.

  • The following 3 methods used in particle kinetics are also used in rigid body kinetics. However, additional equations will come for each method related to the moment effect of forces in rigid body kinetics.

Our basic equation is again F=ma Newton's 2nd law.

1- D’alembert Method (Direct application of the equation F=ma ) : In this method, the acceleration of the object is directly taken into account and solutions are made. It is especially preferred in problems where external forces or acceleration are clear.

2- Work-Energy Method: It is the method preferred more in problems where acceleration is not clear or is not asked.

3 - Impulse_momentum Method: It is especially preferred in problems where external forces change over time or in impact problems. We can reach the result without having to calculate the acceleration. (This topic will be included in the notes later.)

In these notes, the first two methods for planar motion are explained with examples. Now we start to examine these methods.. >>

General Explanations on Rigid Body Kinetics

4. Planar Kinetics of Rigid Body