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Mission SE5 Charging by Induction - Pop Can Induction

 The Question

Two neutral conducting pop cans are touching each other. A negatively charged balloon is brought near one of the cans. The cans are separated while the balloon is nearby. After the balloon is removed can X is ____.

 Physics Rules

Charging by Induction:
Charging by induction is a charging process that involves charging an object without touching the object to a charged object. The charged object is brought near to the object to be charged (a neutral object). The charged object's presence induces a movement of electrons within the neutral object, causing it to become polarized. Then the neutral object is touched to a ground, causing a transfer of electrons between ground the neutral object. The ground is pulled away, the charged object is pulled away and the neutral object has been charged. When the process is complete, both objects are charged with the opposite type of charge.

 Think About It

Opposites attract. Likes repel. And only electrons can move. That's the key to understanding charging by induction. When the balloon is brought near can X, a movement of electrons is induced within can X and can Y. Which way do electrons move? Being repelled by the negatively charged balloon, electrons in can X move to distance themselves from the balloon. Charge is now polarized within the two can system, with can X having lost electrons and can Y having gained electrons. When the cans are separated, each can is charged. Can X is said to have been charged by induction with the negatively charged balloon. Can Y has served as the ground, receiving electrons from can X.

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