Kinematics aims to provide a description of the spatial position of bodies or systems

of material particles, the rate at which the particles are moving (velocity), and the rate at

which their velocity is changing (acceleration). When the causative forces are disregarded,

motion descriptions are possible only for particles having constrained motion namely,

moving on determinate paths. In unconstrained, or free, motion, the forces determine the

shape of the path. In order to describe the motion of an object, first describe its position

where it is at any particular time. More precisely, it is needed to specify its position relative

to a convenient reference frame. Earth is often used as a reference frame, and we often

describe the position of objects related to its position to or from Earth. Mathematically, the

position of an object is generally represented by the variable x.

Dyke (2002) stated that there are a variety of quantities associated with the motion of

objects such as displacement (and distance), velocity (and speed), acceleration, and time.

Knowledge of each of these quantities provides descriptive information about an object's

motion. There are kinematic equations which is a set of four equations that can be utilized to

predict unknown information about an object's motion if other information is known. The

equations can be utilized for any motion that can be described as being either a constant

velocity motion (an acceleration of 0 m/s/s) or a constant acceleration motion. They can

never be used over any time period during which the acceleration is changing. Each of the

kinematic equations include four variables. The values of three of the four variables are

known, then the value of the fourth variable can be calculated. In this manner, the kinematic

equations provide a useful means of predicting information about an object's motion if other

information is known.

Although displacement is described in terms of direction, distance is not. Distance is

defined to be the magnitude or size of displacement between two positions. Note that the

distance between two positions is not the same as the distance traveled between them.
Distance traveled is the total length of the path traveled between two positions. Distance has

no direction and, thus, no sign. According to Corben (2001), in kinematics it is nearly always

deal with displacement and magnitude of displacement, and almost never with distance

traveled. One way to think about this is to assume to marked the start of the motion and the

end of the motion. The displacement is simply the difference in the position of the two marks

and is independent of the path taken in traveling between the two marks. The distance

traveled, however, is the total length of the path taken between the two marks. Displacement

is an example of a vector quantity. Distance is an example of a scalar quantity. A vector is

any quantity with both magnitude and direction.

In recent studies, for a particle moving on a straight path, a list of positions and

corresponding times would constitute a suitable scheme for describing the motion of the

particle. A continuous description would require a mathematical formula expressing position

in terms of time. When a particle moves on a curved path, a description of its position

becomes more complicated and requires two or three dimensions. In such cases continuous

descriptions in the form of a single graph or mathematical formula are not feasible. The

position of a particle moving on a circle, for example, can be described by a rotating radius of

the circle, like the spoke of a wheel with one end fixed at the center of the circle and the other

end attached to the particle. The rotating radius is known as a position vector for the particle,

and, if the angle between it and a fixed radius is known as a function of time, the magnitude

of the velocity and acceleration of the particle can be calculated. Velocity and acceleration,

however, have direction as well as magnitude; velocity is always tangent to the path, while

acceleration has two components, one tangent to the path and the other perpendicular to the

tangent.

Many studies discussed that motion is not with constant velocity nor speed. While

driving in a car, continuously speed up and slow down. A graphical representation of motion
in terms of distance vs. time, therefore, would be more variable or curvy rather than a straight

line, indicating motion with a constant velocity as shown below.

According to Faber (2000), velocity is constantly changing, it can be estimated in

different ways. One way is to look at our instantaneous velocity, represented by one point on

curvy line of motion graphed with distance as against time. In order to determine velocity at

any given moment, the slope should be determined at that point. On the other hand,

acceleration is a vector that points in the same direction as the change in velocity, though it

may not always be in the direction of motion (Drazin, 2000). For example, when an object

slows down, or decelerating, its acceleration is in the opposite direction of its motion.

Many studies emphasized that the motion of an object can be depicted graphically by

plotting the position of an object over time. This distance-time graph can be used to create

another graph that shows changes in velocity over time. As acceleration is velocity in m/s

divided by time in s, it can further derive a graph of acceleration from a graph of an object’s

speed or position. In using the kinematics equations, can make some mathematical

assumptions. When an object in motion moves through the air, air resistance slows the

object’s speed. When using the equations of motion, it is assumed that air resistance is

insignificant enough to ignore. The second assumption we can make when using these

equations involves acceleration. It is already known that acceleration is constant for

kinematics problems, which means that the average acceleration is equal to this value.

Objects in free fall, or projectiles, all experience the same acceleration, regardless of their

mass. This means that whenever an object is thrown, dropped, or falling, it moves with a

constant downward acceleration of equation. It is important to remember that this value is a

magnitude. If it is assumed upwards to be a positive direction or y value, then an object

falling downward will have a negative acceleration of equation.

of both air motion and the motion of patterns describing other properties of air, such as

moisture content, temperature, and pressure (Singh, 2001). This description is without regard

to forces and other physical processes that cause the motions. Air motion itself is an

important causal factor for many of the pattern changes of the other properties of the air.

Daily sequences of weather maps showing horizontal wind flow and the movement of

patterns in pressure and temperature dramatize the kinematic perspective of the atmosphere.
Conclusion
Recent studies highlighted that physics instruction produces only little changes in

students’ conceptual knowledge. The students may know how to use formulas and calculate

certain numerical problems but they still fail to comprehend the physics concepts. The

mentioned studies indicate that instruction can only be effective if it takes into account the

student preconceptions. The proper concepts have to be learned but also the misconceptions

have to be unlearned (Wagner & Vaterlaus, 2011).