Dynamics Chapter 1

Dynamics

Dynamics

Branch of mechanics which deals with the study of bodies in motion

Galileo Galilei

Who derived the Laws of motion and served as the Foundation of Dynamics

Newton’s Second Law of Motion

This law states that the force acting on a body is equal to the rate of change of the body’s momentum.

Galileo Galilei

who made careful observations concerning bodies in free fall, motion on an inclined plane, and motion of pendulum

True

heavy bodies fall more rapidly than light bodies. True or False

Huygens 1657

Who invented the pendulum clock and in what year?

Principia

Newton’s famous work was published in the first edition of _____.

Kinematics

motion of a particle or body without consideration of the forces causing the motion.

Kinetics

branch of mechanics that relates the force acting on a body to its mass and acceleration.

Particle

usually denotes an object of point size

Rigid Body

is a body whose changes in shape are negligible

Rigid Body

a body for which the deformations can be neglected with no loss of accuracy in the analysis of motion

Rectilinear Motion

the motion of a particle along a staright line

displacement

defined as the change in the position of a particle

Speed

Magnitude of velocity

Resultant Force

What is the effective force on a particle?

Newton’s Third Law of Motion

for every force there is an equal and opposite reaction

Inertia Force

If a particle is accelerated by a resultant force, this reaction is called?

False

Inertia Force is equal and directed reaction to the resultant force acting on a particle. True or False

Static equilibrium

If the inertia force is condidered to act on a particle together with the resultant force, the particle will be in ____

Static Equilibrium

the particle is at rest or is moving with constant velocity

D’Alembert’s Principle

Alternative form of Newton’s second law of motion.

Jean le Rond D’Alembert 18th Century

Who and when was D’Alembert’s Principle formulated?

D’Alembert’s Principle

F-ma=0

D’Alembert’s Principle

expresses the relation between the external forces applied to a system of particles and the effective force on each particle of the system

Centroidal Rotation

all particles will describe horizontal circular arcs about the vertical centroidal axis

Plane Motion

since resultant can be transformed into a force acting through the gravity center plus a couple it can be seen that the motion in this case will be a combination of translation and centroidal rotation

Curvilinear Translation

if the direction of R varies, although continuing to pass through the gravity center, so will the motion of the body, resulting in a curved path motion known as

Rectilinear Translation

if the direction of R is constant, the motion of the body follows a straight-line path and is called