Kinematics
We can observe moving objects all around us. The heart pumps blood through the veins even when the person is lying down. Every object is subject to the motion of atoms and molecules. When a player hits the ball with his bat, there is motion.
Kinematics is the branch of classical
mechanics that studies the motion of points, objects, and a group of objects
without taking into account what causes the motion. The Greek word
"kinesis," which means motion, is the origin of the term kinematics.
Astrophysics uses kinematics to investigate the motion of celestial objects. It
is also used in biomechanics and robotics to explain how engines, human
skeletons, robotic arms, and other objects with joint parts move.
In kinematics, we investigate the objects' trajectories and
their distinct properties, such as velocity and acceleration.
Also read: Mammalia
Reference
Frames To comprehend the object's motion, it is
necessary to describe its position in the reference frame. The object's
position is represented mathematically by the variable x. There are two ways to
describe the position variable x. We can choose the positive direction and the
location where x = 0 must be placed. Choosing the coordinate system or frame of
reference is the term for this. The term "frame of reference" refers
to the selection of the coordinate system or set of axes within which the
object's position, orientation, and other properties are being measured.
Displacement refers to the object's shift about the frame of
reference. For instance, the displacement of a person who walks from his house
to the market is the distance between the market and his house (the frame of
reference).
Acceleration and Velocity
The displacement divided by the
time taken is the object's velocity. It has magnitude as well as direction
because it is a vector quantity. Acceleration is the change in velocity's rate.
Kinematics investigates three different kinds of motion graphs.
1. Time graph
2: displacement. Time-velocity graph
3. The
motion diagram is a graphic representation of the object's motion. Acceleration
– Time Graph Motion Diagram A motion diagram depicts the object's various
positions at equally spaced intervals in the same diagram. The diagram
indicates whether the thing has accelerated, slowed, or remained stationary. We
can understand that the object is moving faster if there is more space between
the objects as time goes on and that the thing is moving slower if there is
less space between the objects.
When the initial starting point is taken as the origin and
the object's acceleration is constant, there are four kinematic equations.
1. v = v0 + at
2. d = (½) (v0 + v)t
3. d = v0t + (at2/2)
4. The equations above only contain four of the five
variables: v2 = v02 + 2ad, where v is the final velocity, v0 is the initial velocity,
a is the constant acceleration, t is the time interval, and d is the
displacement. The fourth variable in an equation can be determined if we know
the values of the first three variables.
Equations of rotational kinematics We discovered five significant variables in translational motion. In rotational motion, each of these variables will have a corresponding variable. During a rotation, the angle takes the place of the position variable x. The angular velocity (), which is expressed as radians per second, indicates both the initial and final speeds. The angular acceleration (), which indicates the rate of change in angular velocity over time, takes the place of the acceleration. Radians per square second is the measurement of angular acceleration.
Even in rotation, the time is represented by t. The equations of rotational kinematics are:
1. ω = ω0 + αt
2. θ = θ0 + (½) (ω0 + ω)t
3. θ = θ0 + ω0t + (αt2/2)
Also read: Artificial Biology
Frequently Asked Questions on Kinematics
1. What is meant by kinematics?
The study of bodies' mechanical motion without taking into
account the forces that cause this motion is referred to as kinematics.
2. What is a body's one-dimensional motion?
If a body moves in a straight line, its motion is
one-dimensional.
3. Define motion in two dimensions.
The term "two-dimensional motion" refers to a
body's movement in a plane.
4. Define motion in three dimensions.
Three-dimensional motion occurs when the body moves in a
three-dimensional space.