Question

1. a student moves a charged pith ball on a stick closer to a balloon. the diagram shows the result.

which best explains the result?
a the electric field of the pith ball causes the pull which moves the balloon.
b the electric field of the pith ball causes the push which moves the balloon.
c the gravitational field of the pith ball causes the pull which moves the balloon.
d the gravitational field of the pith ball causes the push which moves the balloon.

Explanation:

1. The balloon moves toward the pith ball, showing an attractive (pull) force.
2. Gravitational forces between such small, light objects are negligible and only attractive, but the key here is the electrostatic interaction between charged objects.
3. The pull indicates the pith ball's electric field exerts an attractive force on the balloon, meaning the two objects have opposite charges.
4. Options B and D are incorrect because they describe a push (repulsion), which does not match the diagram. Option C is incorrect because gravity is not responsible for this observable, strong interaction between small charged objects.

Answer:

A. The electric field of the pith ball causes the pull which moves the balloon.