# Of Chapter 14 (Kinetics Of A Rigid Body: Work And Energy?

720 Words3 Pages
In Chapter 14 (Kinetics of a Particle: Work and Energy) and Chapter 18 (Planar Kinetics of a Rigid Body: Work and Energy), both apply a same concept. It is concept of work and energy to solve the problem. Chapter 14 use the concepts of work and energy to analyze motion of a particle, while Chapter 18 apply work and energy methods to solve planar motion problems. In both chapter, problems that involve force, velocity, and displacement can be solve by using the resulting equation. Chapter 14 states that if the particle acted upon by the force, F undergoes a finite displacement along its path from r1 to r2 or s1 to s2, the work of force F is determined by integration, but in Chapter 18 states that if an external force F acts on a body, the work done by the force when the body moves along the path s. This caused the work of a variable force for both chapters are different which in Chapter 14 the equation for work of a variable force is U1-2 = ∫_r1^r2▒〖F. dr 〗= ∫_s1^s2▒〖F cos θ ds 〗, while the equation for work of a variable force for Chapter 18 is UF = ∫▒〖F . dr=…show more content…
Chapter 14 obtain the principle of work and energy by combined the equation of motion in the tangential direction, ƩFt = mat with kinematics equation at ds = v dv. For application, the free body diagram of the particle should be drawn in order to identify the forces that do work. However, Chapter 18 use kinetic energy that the sum of both its rotational and translational kinetic energy and work done by all external forces and couple moments acting on the body as the body moves from its initial to its final position. For application of Chapter 18, a free-body diagram should be drawn in order to account for the work of all of the forces and couple moments that act on the body as it moves along the