How Can a Fire Door Stay Open and Still Close by Itself?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. How can a fire door stay open and still close by itself?

The Big Idea

In some school hallways, heavy fire doors stay wide open all day. But when there is a fire alarm, they swing closed all by themselves! Let's find out how magnets make that possible.

Held Open by a Magnet

Step one: held open by a magnet. Some fire doors are held open by an electromagnet on the wall. The magnet grabs a steel plate on the door.

The Alarm Rings

Step two: the alarm rings. When a fire alarm rings, the electricity to the magnet is cut. The magnet lets go, and the door swings shut.

Safer Hallways

Step three: safer hallways. Closed doors slow the spread of smoke and fire. They keep hallways safer for everyone.

A Closer Look

Let's take a closer look! The magnet holds the door open. Electricity keeps it strong. The alarm cuts the power. The door swings shut.

Quick Facts

Quick facts! This system is fail safe, because losing power makes the door close. Closed doors slow smoke and fire. The magnet needs electricity to hold the door. Without it, the door closes.

Think Like a Scientist

Now, think like a scientist! With a grown-up, look for a door held open by a wall magnet at school or a store. Draw the magnet. Draw the metal plate. Explain what happens in an alarm. Then explain what you learned to a friend.

Outro

A fire door held by an electromagnet swings shut when the power is cut, keeping hallways safer. Science is amazing! Keep wondering and keep exploring! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!