Using the setup from the first question, imagine that you briefly touch the negatively charged rod to the can (assume that this rod is conducting for the sake of effect). you then hold the two rods at equal distances on either side of the can. what does the can do?

b) rolls toward the positively charged rod

Explanation:

Based on the information provided within the question it can be said that in this scenario the can would roll toward the positively charged rod. This is mainly due to the fact that you briefly touched the can, which caused the can to acquire a net negative charge. This made the can become attracted to the positively charged rod, seeing as opposites attract.

  b.

there are isolated pockets of farming, generally around rivers and oases, which are used for irrigation.