Graphical Representation of Motion 9th Physics Sindh Board

 GRAPHICAL REPRESENTATION OF MOTION

An object is said to be in the state of Motion if it changes its position with respect to its surroundings.

In this article, I will be explaining, "How can we represent the motion of any object graphically?"

Graphical Representation deals with the representation of any thing, lets say motion in our case on graph.
Here we can also observe the relationship between two quantities plotted on x and y axes respectively.

DISTANCE TIME GRAPH

Distance time graph tells us the relationship of distance with the time. 

How an object is changing its position such as speed with respect to the time.

For representation of Distance and time relationship consider an example:

Figure 1: A car covering distances at different intervals of Time

Figure 2: Different distance readings covered by the car at different intervals of time

For example a car is moving and covering different distances at different intervals of time see figure 1 and 2.

As we can observe that time intervals are similar, and the car is covering equal distances at each interval.
Now before discussing its graph since we have two quantities to be plotted on x and y axes.

Since we use to keep the independent quantity on the x-axis. On y-axis dependent quantity always plotted on/ kept on.

    In this case we have Distance which is dependent quantity, we will keep it on Y-axis.

On the other hand, Time is independent quantity to be kept on X-Axis.

Figure 3: Distance-Time Graph

Since we got a straight line, which means the car is covering equal distance in equal interval of Time (Uniform speed). 

The graph of Uniform speed is a straight line.

Consider an other example in which car is covering some time more and some time less distance with respect to time.

Its graph is shown in figure 4.

Figure 4: Graph of Variable Speed

In this graph the car is not covering equal amount of distance in equal interval of time, so it can be said that Car is moving with Variable Speed.

    The graph of Variable Speed/Non-uniform speed is a Curve.

Again consider one more example as shown in figure 5.

Figure 5: Graph of an object at Rest

Now suppose the car is stopped at petrol pump and as you can see the time is increasing but the car's distance is not varying it is constant.

    This shows that the object is at rest for 5 seconds.

The graph of an object at rest is the line parallel to the x-axis.

Speed Time Graph

The speed time graph of any object shows the speed of an object which is either increasing or decreasing with respect to the time.

"The gradient on the speed-time graph is known as Acceleration."

Now let's understand this with few examples;

Consider the car is at rest for the time period of 5 seconds as shown in figure 6.

Figure 6: The car is at rest for the time interval of 5 seconds

Since the car is at rest, so its speed will be zero. 

Now the car start to move steadily with the speed of 20m/s for 5 seconds as shown in figure 7.

        Figrue7: The car is moving with 20m/s speed 

And since distance is the product of speed and time so, the distance covered by car in this case is 100m.

                => distance = speed * Time

                => distance= 20*5 = 100m