When an object moves while rotating along a circular path, it is said to be in circular motion. Circular motion is further divided into two categories: uniform and non-uniform circular motion.
In our previous post, we explored uniform circular motion. Now, let’s turn our attention to non-uniform circular motion. This occurs when an object moves along a circular path but its speed changes instead of staying constant. In some cases, the distance between objects moving in such a path can also vary as their motion speeds up or slows down.
Examples of Non Uniform Circular Motion in Everyday Life
- 1. A car turning around a bend while speeding up or slowing down
- 2. A roller coaster looping the loop
- 3. A ceiling fan that is turning on or off
- 4. A cyclist on a circular track who pedals harder on straight stretches and eases up on curves
- 5. The Moon in its slightly elliptical orbit
- 6. A person walking in a circle
- 7. A bouncing ball
- 8. A washing machine during a spin cycle
- 9. A helicopter rotor during takeoff or landing
- 10. A potter’s wheel
1. A car turning around a bend while speeding up or slowing down
When a car goes around a curve and the driver presses the accelerator or brake, the car’s speed is constantly changing. Even though it stays on a curved path, the increase or decrease in speed makes the motion non-uniform. The car is either gaining or losing momentum as it travels around the bend.
2. A roller coaster looping the loop
As a roller coaster climbs the top of a loop, it slows down because it’s working against gravity. Then, as it rushes downward, it speeds up again. The track forms a circle, but the changing speed as it goes up and down makes this a perfect example of non-uniform circular motion.
3. A ceiling fan that is turning on or off
When you switch on a ceiling fan, the blades don’t instantly spin at full speed—they gradually pick up speed. When you turn it off, they slowly lose speed until they stop. The blades stay in a circular path the whole time, but because the speed isn’t steady, the motion is non-uniform.
4. A cyclist on a circular track who pedals harder on straight stretches and eases up on curves
If a cyclist pedals faster on one part of the track and slows down on another, the speed keeps changing even though the path is a circle. This stop-and-go pattern means the motion isn’t uniform. The cyclist is still moving in a circle, but not at a constant rate.
5. The Moon in its slightly elliptical orbit
The Moon’s path around Earth is almost a circle but not perfectly so, and its speed changes slightly as gravity pulls on it more strongly at different points. Sometimes it moves a bit faster, and other times a bit slower. This gentle speeding up and slowing down makes its motion non-uniform.
6. A person walking in a circle
Someone walking around a circular path rarely keeps the exact same pace the whole way. They might slow down to check their phone or speed up to catch up with a friend. Because the speed isn’t perfectly steady, the motion is non-uniform even though the path is circular.
7. A bouncing ball
If a ball is bounced while being moved in a circular path—like swinging a ball on a string or dribbling while walking in a circle—its speed changes each time it bounces. Each bounce causes small slowdowns and speedups, so the circular motion isn’t uniform.
8. A washing machine during a spin cycle
When you turn on the spin cycle, the drum doesn’t jump to top speed instantly. It speeds up, keeps spinning, then slows down at the end. The clothes move in a circular path, but the changing speed makes it non-uniform.
9. A helicopter rotor during takeoff or landing
When a helicopter takes off, the rotor blades gradually speed up to lift the aircraft. During landing, they slow down again. Even though the blades trace a circular path, their changing speed shows clear non-uniform circular motion.
10. A potter’s wheel
When a potter presses the pedal to start or stop shaping clay, the wheel slowly speeds up or slows down. It keeps rotating in a circle, but because the speed is constantly being adjusted, the motion is non-uniform.