Difference between Uniform and Non-Uniform Motion

A ball cannot change its position on its own or unless we apply force on the ball. The ball will move or change its position only when we apply force on it. This change in the position of any object is called motion. For example, a boy sitting on a bicycle. Here the cycle is in rest and will remain in the rest position until the force is applied on the foot pedal. When the boy applies force on the pedal, the cycle will start moving or there will be a change in the position of the bicycle.

To understand motion in a better way, you have to first understand speed, distance, velocity, which are described as follows;

Speed: Speed is a distance of an object covered in a given amount of time. It basically tells how fast something travels whether it be an object or person. To find the speed, we require time and distance. Similarly, we can find the distance if speed and time are given. Speed offers only the magnitude, and we called it scalar quantity in physics. Speed does not specify the direction. It just tells us how much area is covered in unit time without considering the direction of travel in which direction the object moves.

• Uniform Speed:An object that covers an equal distance in equal intervals of time is said to have a uniform speed.
• Non-uniform Speed:It is the speed in which the distance covered by the object is not equal in equal intervals of time. For example, consider a rubber ball dropped from a height, and it bounces many times. The bounce height is different in each bounce. The distance covered by the ball is different in each bounce or in equal intervals of time, so it is an example of non-uniform speed.

Velocity: Velocity is like speed but here we have to specify the direction in which an object is moving. We can say that it is the rate of change of position per unit time or displacement per unit time.

• Uniform velocity:The equal displacement occurs in equal time intervals, it is called uniform velocity. Here, the object moves in a fixed direction.
• Non-uniform velocity:When unequal displacement occurs in the same time interval, it is called non-uniform velocity. It is also known as variable velocity.

Uniform Motion

When an object covers equal distance in equal intervals of time, it is called uniform motion. Consider a car or bike is covering 15 km in 15 minutes and the next 15 km in 15 minutes and so on, so, it is called uniform motion.

Cases of uniform motion:

1. No change in velocity
2. No change in acceleration
3. No change in Speed
4. No Change in direction

Uniform circular motion

When an object is moving in circles at uniform Speed, it is called uniform circular motion. An example of a uniform circular motion is the fan. When you switch on the fan and give some time to the fan to reach its fixed speed then the fan is showing uniform circular motion. So the motion of the fan is a uniform circular motion. In that, velocity is not constant as speed is constant, but the direction is not constant or it keeps changing. Similarly, when you are walking around the room in a circle, your direction is changing all the time. That's why velocity is not uniform or constant.

How to calculate the speed of uniform circular motion

We know speed is the distance by time. Let's see the body takes 't' seconds to complete one full circle. So the distance travelled here is the circumference of the circle, which is 2πr, where r is the radius.

So, Speed = (2πr)/t

Non-uniform Motion

It is a motion in which unequal distance is covered in equal intervals of time. For example, a car covers the distance of 20 km in 10 minutes and then it covers 10 km in the next 10 minutes then it is showing non-uniform motion as the car covers uneven distances in equal time intervals. So, when an object covers the uneven distances in the same amount of time, it is called non-uniform motion.

Three cases of non-uniform motion:

1. When speed changes
2. When direction change
3. When direction and speed both changes

Non-uniform circular motion:

If the speed of the particle keeps changing while revolving in a circle, it is known as non-uniform circular motion. During the non-uniform circular motion of a particle, both the particle's speed and angular velocity are changed.

Difference between Uniform and Non-Uniform Motion