Calculation of Motion using Kinematic Equation

Calculation of motion using Graphs

The calculation of motion can be solved using kinematic equation through graphical representation. Use of velocity time graphs are used for the determination of values and their relationship with the quantities of displacement.

Let us consider an object moving with a constant velocity of +5 m/s for a given time period of +15 m/s over a period of 5 seconds. This verbal description of motion, can also be represented with the use of velocity-time graph.

The constant velocity motion is depicted through the horizontal section of this graph, which is exactly similar to the verbal representation of motion as stated above. The upward slope, which is the positive slope in the graph represents positive acceleration, similar to the description where the object moves in positive direction with a speed periodically increasing from 5 m/s to 15m/s. The slope can be calculated with the use of rise over run ratio. This is derived from the rise of speed in between 5 to 10 seconds, the line rises from 5m/s to 15m/s with an overall run of 5 seconds. Therefore the slope is (10m/s)/(5 m/s) = 2m/s² .

Equation of Motion

There are three equations of motion in case of uniform acceleration, also known as laws of constant acceleration. The various components are velocity ( initial and final) , time (t), displacement (s), and acceleration (a). Thus, these can only be used where motion is a straight line and acceleration is constant.

• v = u + at
• v² = u² + 2as
• s = ut + ½ at ²