Question

three neutral metal cans mounted on isulating stands are touching a negatively charge ballon is brought near can a can b is then removed. what is the charge of a? what is the charge of can c?

Answer 1

When a negatively charged balloon is brought near three neutral metal cans, the cans become positively and negatively charged through charge induction. Can A will have a positive charge and can C will have a negative charge.

Step-by-step explanation:

When the negatively charged balloon is brought near the three neutral metal cans, the negative charge on the balloon induces a separation of charges in the metal cans. The side of the cans facing the balloon becomes positively charged, while the opposite side becomes negatively charged. This is known as charge induction.

When can B is removed, can A and can C remain connected. Can A will have a positive charge because it was induced by the negative charge on the balloon and the absence of can B. Can C will have a negative charge because it was close to can B, which was negatively charged.

Answer 2

Charge on can A is positive.
Charge on can C is negative.
Punctuation and capitalization are very useful things to pay attention to and this question would be a lot easier to understand if you had actually used both capitalization and punctuation. If I'm understanding the question, you have 3 metal can that are insulated from the environment and initially touching each other in a straight line. Then a negatively charged balloon is brought near, but not touching one of the cans in that line of cans. While the balloon is near, the middle can is removed. Then you want to know the charge on the can that was nearest the balloon and the charge on the can that was furthermost from the balloon.
As the balloon is brought near to can a, the negative charge on the balloon repels some of the electrons from can a (like charges repel). Some of those electrons will flow to can b and in turn flow to can c. Basically you'll have a charge gradient that's most positive on that part of the can that's closest to the balloon, and most negative on the part of the cans that's furthest from the balloon. You then remove can B which causes cans A and C to be electrically isolated from each other and prevents the flow of elections to equalize the charges on cans A and C when the balloon is removed. So you're left with a deficiency of electrons on can A, so can A will have a positive overall charge, and an excess of electrons on can C, so can C will have a negative overall charge.