Lesson 1 Flashcards
is the study of forces that act on bodies and the resultant motion that those bodies experience.
Mechanics
is the basis of all the mechanical sciences: civil engineering, materials science and engineering, mechanical engineering, aeronautical and aerospace and engineering.
Engineering Mechanics
2 Branches of Engineering Mechanics
- Statics
- Dynamics
is the branch of mechanics that is concerned with analysis of loads acting on physical systems that do not experience acceleration, but rather, are in static equilibrium with their environment.
Statics
branch of physical science and subdivision of mechanics that is concerned with the motion of
material objects in relation to the physical factors that affect them: force, mass, momentum, energy.
Dynamics
Dynamics has two distinct parts:
- kinematics
- kinetics
which is the study of motion without reference to the forces which cause motion
kinematics
which relates the action of forces on bodies to their resulting motions.
kinetics
The beginning of a rational understanding of dynamics is credited to __________________, who made
careful observations concerning bodies in free fall, motion on an inclined plane and motion of the pendulum.
Galileo (1564-1642)
He was largely responsible for bringing a scientific approach to the investigation of physical problems.
Galileo (1564-1642)
Perhaps Galileo’s greatest contribution to physics was his formulation of the concept of ________
inertia
an object in a state of motion possesses an “_____________” that causes it to remain in that state of motion unless an external force acts on it.
inertia
guided by Galileo’s work, he was able to make an accurate formulation of the laws of motion and, thus, to place dynamics on a sound basis.
Isaac Newton (1642-1727)
A body at rest will remain at rest and a body in motion will remain in motion (in a straight line with a constant speed) unless it is acted upon by an external (unbalanced) force.
NEWTON’S FIRST LAW OF MOTION (inertia)
The acceleration of an object is directly proportional to the net force and inversely proportional to its mass
NEWTON’S SECOND LAW OF MOTION (acceleration)
forms the basis for most of the analysis in dynamics. For a particle of mass m subjected to a resultant force F.
Newton’s second law
it states that for every action, there is an equal and opposite reaction
NEWTON’S THIRD LAW OF MOTION
It is the location of the particle with respect to the chosen reference point.
POSITION
Represents the continual change in an object position.
MOTION
is a scalar quantity that refers to “how much ground an object has covered” during its motion.
DISTANCE
is defined as the change in position of an object.
DISPLACEMENT
It is a vector quantity and has a direction and magnitude.
DISPLACEMENT
It is represented as an arrow that points from the starting position to the final position.
DISPLACEMENT
Tells the rate of change of motion of an object. It doesn’t care about the direction. (Scalar quantity)
SPEED
Tells the rate of change of motion of an object. It ascertains the object’s speed and the direction it takes while moving. (Vector quantity)
VELOCITY
The quantity that tells us how fast an object is moving anywhere along its path
INSTANTANEOUS VELOCITY
usually simply called velocity
INSTANTANEOUS VELOCITY
It is the average velocity between two points on the path in the limit
that the time (and therefore the displacement) between the two points approaches zero.
INSTANTANEOUS VELOCITY
is the limit of the average velocity as the elapsed time approaches zero, or the derivative of x with respect to t
INSTANTANEOUS VELOCITY
is the average rate of change of position (or displacement) with respect to time over an interval.
AVERAGE VELOCITY
Tells how fast the velocity changes under a period.
ACCELERATION
It is the rate of change of the velocity of an object with respect to time. It is a vector quantity
ACCELERATION
An object is said to be in a ________________ when the object moves in a straight line.
Linear Motion
There are two types of linear motion, and they are __________ and ___________
uniform motion and non-uniform motion.
An example of this motion is: Athlete running 200m along the straight track.
Linear Motion
An object is said to be in a _______________ when two objects are moving in a straight line and are parallel to each other.
rectilinear motion
An example of this motion is: Elevator movement
Rectilinear Motion
is another name for straight-line motion.
Rectilinear motion
This type of motion describes the movement of a particle or a body.
Rectilinear motion
A body is said to experience _________________ if any two particles of the body travel the same distance along two parallel straight lines
rectilinear motion
When an object travels at a constant speed with zero acceleration it is known as _____________
Uniform rectilinear motion
When an object travels at an irregular speed and acceleration it is known as __________________
Uniformly accelerated rectilinear motion/rectilinear movement with non-uniform acceleration.
