Why do you feel wind in a subway station before the train comes?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do you feel wind in a subway station before the train comes?

The Big Idea

Waiting for the subway, you may feel a breeze. Then the train arrives! Where does the wind come from?

Air Piston

Step one: Air Piston. A train moving in a tunnel pushes a column of air ahead of it. It works like a piston in a bicycle pump.

Into the Station

Step two: Into the Station. The air has nowhere to go but through the tunnel and into the station. So you feel a breeze before the train arrives.

Pulling Air

Step three: Pulling Air. When the train leaves, it pulls air along after it. Always stand back from the platform edge.

A Closer Look

Let's take a closer look! The train moves in. It pushes air. Air rushes into the station. Vents let it out.

Quick Facts

Quick facts! Subway systems use vents to let the moved air out. Stand behind the yellow line. Like a bicycle pump. The breeze means a train is near.

Think Like a Scientist

Now, think like a scientist! Press down on a bicycle pump with the hose open. Hold your hand near the end of the hose. Feel the air rush out. How is this like a train in a tunnel? Try pushing slowly and quickly.

Outro

You feel wind in a subway station before the train comes because the train pushes a column of air through the tunnel like a pump piston. Always stand back from the platform edge. Science is amazing! The world is full of surprises. Keep asking big questions, and keep exploring with me! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!