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Uniform motion., .When an object covers equal distances in equal intervals of time however small or big the time interval may be, the object is said to have uniform motion.

The simplest of all motions is uniform motion that we come across in our day-to-day life, although most of the motions are not uniform^ Let us consider an example. A car, starts from O and after 15 seconds it reaches A covering a distance of 20 metres from the origin (Fig. 1.10). In next 15 seconds it reaches B covering a distance of 40 metres from origin and in next 15 seconds it reaches C covering a distance of 60 metres from origin.

In this case the car covers a distance of 20 metres in each 15 second interval. It means that the distance covered by the car is directly proportional to the time. If we-plot a

graph between distance and time for this motion it comes but to be a straight line (we will be discussing more about it later in this chapter) and is known as uniform motion graph (Fig. 1.11

graph between distance and time for this motion it comes but to be a straight line (we will be discussing more about it later in this chapter) and is known as uniform motion graph (Fig. 1.11).

Non-uniform motion. When an object covers unequal distances in equal intervals of time, however small or big the time interval may be, the object is said to have non-uniform motion. Most of the motions which we come across in our daily life are non-uniform, e.g., motion of a bus on a road. When the bus starts, its speed is very slow, it gains speed for some time, and reaches a maximum value. Again, it slows down as it reaches near the next stop and finally stops there. Here the bus is covering different distances in equal intervals of time and hence it is not moving at a uniform speed. Such motions where distance travelled is not equal in equal intervals of time is called non-uniform motion. Similarly, motion of train, running athlete etc. are all examples of non-uniform motion.

Let us consider another example in which a car is moving on a busy road. It reaches a point A which is 20 metres from origin in 15 seconds and in next 15 seconds it reaches at point B, which is 60 metres from the origin. In next 15 seconds it reaches at point C which is 70 metres from the origin (Fig. 1.12).

In each case, car covers unequal distances in equal intervals of time and the motion is considered as the non-uniform. If we plot, the graph between distance-time, it will not be a straight line. It will be a curved path (the shape of the curve depends upon, the nature of. the motion) (Fig. 1.13).

Hope this helps!!