A paper clip will be suspended from a string inside a Styrofoam cup surrounded by aluminum foil. Predict what will happen to the paperclip when a charged rod is brought near the cup.

The clip will experience no force from the charged rod.

Explanation:

If a charged rod is brought near the cup, it wil cause that opposite charges travel to the outer surface of the aluminum foil, and like charges move to the inner surface, as charges can move freely in a conductor, and the aluminum foil must remain neutral.The charges on the inner surface, will attract opposite charges to the surface of the cup, and will repel like charges in the opposite direction, towards the paper clip.As the Styrofoam can be considered as a good insulator, charges can move very little distance within it, so the part of the cup facing the paper clip, will remain neutral, for normal cup thickness.As consequence, the paper clip will experience no force due to the presence of the charged rod.

It's because 3 if it was 10 it wouldn't look right do it goes up to 4d

The independent variable would be the fertilizer as it is what the dependent variable (the growth of grass) depends on.