Uniform and Non Uniform Motion
An object is said to be in uniform motion if it covers equal distances in equal intervals of time how so ever big or small these time intervals may be.
For example, suppose a car covers 60 km in first hour, another 60 km in second hour, and again 60 km in the third hour and so on. The motion of the car is uniform. Let us now understand the meaning of the words “how so ever small the time interval may be” used in the definition. In this example, the car travels a distance of 60 km in each hour. In the striker sense, the car should travel 30 km in each half an hour, 15 km in every 15 minutes, 10 km in every 10 minutes, 5 km in every 5 minutes and 1 km in every 1 minute. Only then the motion of the car can be said to be uniform.
An object is said to be in non uniform motion if it covers unequal distances in equal intervals of time.
Consider a bus starting from one stop. It proceeds slowly when it passes crowded area of the road. Suppose, it manages to travel merely 100 m in 5 minutes due to heavy traffic, when it gets out and the road is clear, it speeds up and is able to travel about 2 km in 5 minutes.
We say, the motion of the bus is non uniform i.e. it travels unequal distances in equal intervals of time.