Vortex

Let's break down the principle behind this fascinating experiment in a simpler way:
Principle: The Vortex Dance, when you spin the tube with water inside, you're actually making the water do a special dance called a vortex. This dance happens because of two important forces: centrifugal force and cohesive force.
Centrifugal Force: Imagine you're spinning around really fast. You feel like you're getting pushed away from the center, right? That's the centrifugal force. When you spin the water in the tube, it feels the same way – the water at the center gets pushed outward.
Cohesive Force: Now, think of the water molecules as friends holding hands. They like to stick together because of something called cohesive force. It's like when you and your friends form a circle and hold hands.
What Happens in the Vortex Dance?
Spinning Fast: When you spin the tube, the water inside starts spinning too. But here's the cool part – the water in the center spins faster than the water near the edges.
Centrifugal Force Takes Over: At the center, the spinning is so fast that the centrifugal force becomes really strong. It's like a superhero force pushing the water molecules away from the center.
Vortex Forms: Because the centrifugal force is so strong, it creates a hole in the middle – the vortex. This is where the water can't hold hands anymore because the force pushing outward is stronger than the force holding them together.
Air Sneaks In: The hole in the middle lets air sneak in because there's less water there. This is why you see the water spiraling down – it's like a magical waterfall inside the tube!
Conclusion: So, when you see the vortex in the spinning water, you're actually watching a dance between the forces that want the water to spread out and the forces that want the water to stay together. It's like a watery ballet, and the vortex is the star of the show!