Five styrofoam balls are suspended from insulating threads.Several experiments are performed on the balls and the followingobservations are made:
I. Ball A attracts B and repels C
II. Ball D attracts B and has no effect on E
III. A negatively charged rod attracts both A and E
What are the charges, if any, on eachball?
A B C D E
A) + - + 0 +
B) + - + + 0
C) + - + + 0
D) - + - 0 0
E) + 0 - + 0
The answer is D.
I understand that A and C have to have the same signs and that B is the opposite sign of A and C. What I don't understand is why D and E are 0.
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remove the brackets to see the diagram sorry
To determine the charges on each ball, let's analyze the given observations:
I. Ball A attracts B and repels C:
From this observation, we can conclude that the charge on Ball A must be opposite to the charge on Ball B, and the charge on Ball C must be the same as Ball A.
II. Ball D attracts B and has no effect on E:
Based on this observation, we can conclude that Ball D carries no charge since it has no effect on Ball E.
III. A negatively charged rod attracts both A and E:
According to this observation, Ball A is attracted to the negatively charged rod, indicating that Ball A must be positively charged. Similarly, Ball E is also attracted to the negatively charged rod, implying that Ball E is also positively charged.
Using this information, we can now determine the charges on each ball:
A: + (positively charged)
B: - (negatively charged, opposite to Ball A)
C: + (same as Ball A)
D: 0 (no charge, as it has no effect on any ball)
E: 0 (no charge, as it is attracted to the negatively charged rod, suggesting no charge)
Therefore, the correct answer is option D: -,+,-,0,0.
Based on the given observations, we can infer the charges on each ball as follows:
I. Ball A attracts B and repels C:
From this observation, we can deduce that Ball A and Ball B have opposite charges since they attract each other. Similarly, Ball A and Ball C have the same charges since they repel each other.
II. Ball D attracts B and has no effect on E:
This observation tells us that Ball D and Ball B have opposite charges since they attract each other. However, Ball D has no effect on Ball E, suggesting that Ball D is neutral or has no charge.
III. A negatively charged rod attracts both A and E:
This observation indicates that Ball A and Ball E both have charges opposite to that of the negatively charged rod. Therefore, Ball A and Ball E have the same charges, which are opposite to the charge of the rod.
Given these conclusions, we can determine the charges on each ball:
A) + - + 0 +
B) + - + + 0
C) + - + + 0
D) - + - 0 0
E) + 0 - + 0
From the options, the correct answer is D, where Ball A has a negative charge, Ball B has a positive charge, Ball C has a negative charge, Ball D is neutral (has no charge), and Ball E is neutral (has no charge).