C. Moving Balloon 1 can make Balloon 2 move without the balloons touching.
Explanation:
When two balloons are rubbed with a wool cloth, they get electrostatic charge and both become negatively charged.
If both balloons will be place close together, balloon 1 will push the balloon 2 far from itself without touching it as they both are negatively charged and things with same charges repel each other.
Hence, the correct answer is "C. Moving Balloon 1 can make Balloon 2 move without the balloons touching."
the cart will be slowed down because the weight was added to the right the cart won't stop for about 10 seconds. there will be a lot of pull and friction therefore the cart slows down drastically