1. What Is Non-uniform Motion?
Non-uniform motion occurs when an object covers unequal distances in equal intervals of time. This means the speed or velocity keeps changing.
Most real-life motion is non-uniform because objects speed up, slow down, or change direction frequently.
1.1. Changing Speed or Direction
In non-uniform motion, the speed may increase, decrease, or vary irregularly. Even if speed stays the same but direction changes, the motion becomes non-uniform.
1.2. Acceleration in Non-uniform Motion
Because velocity keeps changing, the object has acceleration. This acceleration may itself change over time.
2. Characteristics of Non-uniform Motion
Several clear features help us identify non-uniform motion.
2.1. Unequal Distances in Equal Times
If an object covers different distances in each second, minute, or hour, it is not moving uniformly.
2.2. Variable Speed
Speed is not constant. It may rise or fall depending on the situation. The object may also stop for a moment.
2.3. Non-zero and Changing Acceleration
Acceleration exists because velocity changes. Since the motion is irregular, acceleration is usually non-uniform.
3. Distance–Time Graph for Non-uniform Motion
Graphs are a helpful way to understand non-uniform motion visually.
3.1. Curved Graph
A distance–time graph for non-uniform motion is usually a curved line. The curve shows that distance increases at a changing rate.
3.2. Slope Changes Over Time
The slope (which represents speed) is not constant. It may become steeper or gentler, indicating changes in speed.
4. Examples of Non-uniform Motion
Most natural and real-world motion is non-uniform because objects rarely move at a fixed speed for long periods.
4.1. Everyday Examples
- A car moving in city traffic—speeding up, slowing down, stopping.
- A child running and changing pace frequently.
- A roller coaster speeding up while going down and slowing on slopes.
- A cyclist on uneven roads.
5. Why Non-uniform Motion Is More Common
In real life, various factors cause speed and direction to change frequently, making non-uniform motion far more common than uniform motion.
5.1. Factors Causing Non-uniform Motion
- Traffic lights and stops.
- Road bends and turns.
- Slopes and uneven surfaces.
- Weather conditions like wind or rain.
- Human reactions and decisions.