[Physics Class Notes] on Uniform Motion and Non Uniform Motion Pdf for Exam

In our day-to-day life, we see several motions of living and non-living objects, whether birds, animals, fishes, cars, trains, etc. So, what common do you find in their motions? 

Also, we say that an object can be uniform or non-uniform motion. However, a question arises: why do we categorise the motion of an object into two types? 

So, how do we differentiate between uniform and non-uniform motion? Well! There are various parameters, such as average speed, distance covered by an object, and so on. Also, we will follow the mathematical approach, like graphs on each type of motion.

Now, let us start our article with the definition of both types of motion, along with illustrating examples on both.

Definition of Uniform and Non-uniform Motion

1. Uniform Motion

The type of motion in which the object travels in a straight line with uniform speed, is called Uniform motion. This means that the velocity of the body remains constant as it covers equal distances in equal intervals of time. In the case of uniform rectilinear motion, the acceleration of the body will be zero. Here, the average speed of the object will be equal to the actual speed. Examples of uniform motion are a car moving with constant velocity, a boy running in a straight path with constant speed etc.

2. Non-uniform Motion

The type of motion in which the object travels with a varied speed is called Non-Uniform Motion. This means that the object does not cover equal distances in equal time intervals. If the motion is not consistent in the case of rectilinear motion, the acceleration of the body will be non-zero. For example, the motion of a vehicle is an oscillation of a pendulum. Non-uniform motion is also called accelerated motion.

Differentiate between Uniform and Nonuniform Motion

Below is the tabular difference between uniform and nonuniform motion:

How is Uniform Motion Different from Nonuniform Motion?

From the above table, we understand that in uniform motion, the velocity of the body travelling in a straight line remains the same. Also, the distance travelled by a moving object is the same at several time intervals. Thus regardless of the time length, the motion is said to be uniform.

Below is the distance-time graph for the uniform motion:

The graph given above, it is indicated that there is a shift of 10 meters every minute, as there is a constant velocity with respect to time.

Slope = dxdt = Distance/time

Here, we will prove that velocity ‘v’ is constant.

So, let us take some values:

Using the above equation, calculate the value of velocity:

1. x1/t1 = 10/1 = 10 m/min

Similarly, for the remaining values:

2. 20/2 = 10 m/min

3. 30/3 = 10 m/min

We find that the value of velocity remains the same, which means the motion is uniform.

Now, let us understand what nonuniform motion is.

We studied from the above text a body that covers unequal distances in equal intervals of time; it possesses a nonuniform motion.

Below is the formula for unequal distances in equal intervals of time:

For example, a ball is freely falling and moves 6 metres in the 1st second, 12 metres in the 2nd second, and so on. Thus, a freely falling ball will cover smaller distances in the first ‘1 second’ and larger distances in the later ‘1 second’ intervals. Hence, we can say that the motion of a freely falling ball is an example of a non-uniform motion.

The distance-time graph of the non-uniform motion is a curved line. Non-Uniform motion is also known as accelerated motion. 

Below is the diagram of the motion having a nonuniform motion:

Image: “Distance-time graph of a body making nonuniform motion”

Now, let us go through examples of uniform and nonuniform motion.

1. Uniform motion examples

2. Non-Uniform Motion Examples

Most of the motions around us are non-uniform in nature. Some of them are

• A horse running

• A man running in a 100m race

• A bouncy ball

• A car colliding with another car

• Plane moving through the clouds and then landing

• Dragging a box from a path

• A bus on its way through the market

• A train coming to its terminating spot

• Movement of an asteroid

Quiz on Non-uniform Motion

1. How Can You Tell that an Object Exhibits Non-uniform Motion from a Position-time Graph?

1. Nonuniform motion generates a straight line position-time graph that has a slope greater than 10.

2. Nonuniform motion generates a position-time graph that is not straight but is curved instead.

3. Non-uniform motion generates a position-time graph that is a straight line with a slope less than 1.

4. Non-uniform motion generates a position-time graph that is a vertical line.

Ans: Option b

Explanation: The graph for a body possessing nonuniform motion is a curved line.