# sol22 - negative charge and, thus, the leaves have a larger...

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PHYSICS 103 Chapter 20 -- HW #22 Questions 12. The mostly likely behavior for a third kind of charge would be to attract both existing kinds of charge and repel itself. 16. Because balls 2 and 3 repel each other, we know that both balls are charged. Repulsion only occurs between charged objects. On the other hand, attraction only means that one of the two objects is charged. Both could be charged, but this is not necessary. Therefore ball 1 could be neutral. It could also have the opposite charge of balls 2 and 3. 24. We can use a negatively charged rod to determine the sign of the unknown charge on an electroscope. Slowly bring the charged rod close to but not touching the ball of the electroscope. If the leaves spread further apart, the electroscope has a negative charge. The negative rod pushes negative charges down to the leaves, leaving the leaves with a larger
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Unformatted text preview: negative charge and, thus, the leaves have a larger separation. (Or the you can imagine the rod pulling positive charge from the leaves with the same result.) If the leaves fall closer together, the electroscope has a positive charge. The negative rod pushes negative charges down onto the leaves, canceling part of the positive charge and, thus, the leaves have a smaller separtation. Exercise 2. The protons each carry one unit of positive charge, while the neutrons are neutral; that is, they are not charged. Therefore, the nucleus has 92 units of positive charge. We can go further and compute the charge in coulombs. In the Computing Box on page 427 or in the list of Physical Constants on the last page of the text, the size of the elementary charge is given. Therefore, ( 29 ( 29 19 17 92 1.6 10 C 1.47 10 C q ne--= = =...
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## This document was uploaded on 10/29/2011 for the course PHSX 103 at MSU Bozeman.

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