Uniform and Non-Uniform Motion: Definition and Differences

Introduction Uniform and Non-Uniform Motion

Moving objects move in many different ways. Some move fast and some slowly. Objects can also move in different kinds of paths. We shall categorize the motions done by objects into two categories based on the pattern of their pace of motion in this session.

Explanation:

Uniform Motion:

Let us consider the movement of the hands of a clock. It has three hands, namely, the second hand, the minute hand, and the hour hand. All of them move in circles showing us the time of the day/night. There is a pattern of motion that each one of them follows.

The tip of the second’s hand moves the exact same distance every second. The tip of the minute hand moves the exact same distance every minute. The tip of the hour hand moves the exact same distance every hour.

Such motions where a body covers equal distances in equal intervals of time are called uniform motions. Hence, the hands of a clock are in uniform motion.

When a body covers equal distances in equal intervals of time, it is said to be in a uniform motion. A uniformly moving body moves at the same pace throughout its motion.

There can be many examples of bodies in uniform motion.

1. A car moving at the same pace throughout its motion
2. The rotation of the Earth about its axis every 24 hours
3. The revolution of the Earth around the sun every 365 days
4. The motion of the blades of a fan at a particular set speed  

Fig 2: Examples of uniform motion

In a periodic motion, the object repeats its motion after a fixed time interval. Hence, all periodic motions can be categorized under uniform motion.

Fig 3: Periodic motions as uniform motion

Non-uniform Motion:

Consider the fish swimming in a water body. The swimming fishes cover unequal distances every second/minute/hour. They move randomly, i.e., sometimes slow, sometimes fast, and sometimes they halt.

There can be several other examples of non-uniform motion. Some of them are as follows:

1. A car changing its pace of motion throughout its motion
2. The motion of the ants
3. The motion of a snake
4. The motion of flying birds

Fig 4: Non-uniform motion – Examples

When a body covers unequal distances in equal intervals of time, it is said to be in a non-uniform motion.

A non-uniformly moving body can be found to move at different paces throughout its motion.

Questions and Answers:

1. The person peddles his bicycle in such a way that one round of the wheels takes exactly 2 seconds. What kind of motion is he making? Uniform or non-uniform?

Answer:

The person is in a uniform motion as he would cover an equal distance in equal intervals of time.

2. Is the spinning of the Earth about its axis a uniform motion?

Answer:

Yes, the spinning of the Earth about its axis is a uniform motion because it takes approximately 24 hours to complete one rotation. It always takes 24 hours to complete a rotation.

Summary

• When a body covers equal distances in equal intervals of time, it is said to be in a uniform motion.
• A uniformly moving body moves at the same pace throughout its motion.
• When a body covers unequal distances in equal intervals of time, it is said to be in a non-uniform motion.
• A non-uniformly moving body can be found to move at different paces throughout its motion.