Question
Three small Styrofoam balls arc suspended from thin threads. Various object;, are then rubbed against each other (wool against plastic, silk against glass, etc.) and each Styrofoam ball is charged by touching it with one of these objects. It is found that balls I and 2 repel each other and dial balls 2 and 3 attract each other From this we can conclude that (check all that apply) 1 and 2 carry charges of the opposite sign 1 and 2 carry charges of the same sign 2 and 3 carry charges of the same sign 2 and 3 carry charges of the opposite sign all three objects carry charges of the same sign we need to do more experiments to determine the sign of the net charge on each ball 1 and 3 carry charges of the same sign 1 and 3 carry charges of the opposite sign
Explanation / Answer
here we obsrved two main principles
basing on propertics of electrostatices
like charges are repel each other
unlike charges are attreck eachother
so the point we observed is
1 and 2 are carries charges of same signs
2 and 3 carries charges of opposite signs
1 and 3 carries charges of opposite sign