Asked by Sophea

A student hangs two inflated balloons from 1-meter strings so that they touch. The student then holds the balloons apart and rubs each balloon 5 times with animal fur. The student then releases the balloons. The balloons now hang a small distance apart from one another:

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The next step in the student's procedure is to touch the balloons with a metal rod and allow them to settle, and then to rub them 10 times with animal fur. Which result should the student expect, and why?

Responses

The balloons will hang at the same elevation, because electrical repulsion is an unvarying phenomenon which results from the existence of charge and not its quantity.
The balloons will hang at the same elevation, because electrical repulsion is an unvarying phenomenon which results from the existence of charge and not its quantity.

The balloons will hang straight down or more closely together, because a larger number of rubs with fur will give them opposite rather than like electrical charges.
The balloons will hang straight down or more closely together, because a larger number of rubs with fur will give them opposite rather than like electrical charges.

The balloons will hang at a smaller elevation, because more thoroughly rubbing them will more completely remove their charges, reducing the electrical repulsion between them.
The balloons will hang at a smaller elevation, because more thoroughly rubbing them will more completely remove their charges, reducing the electrical repulsion between them.

The balloons will hang at a greater elevation, because they will have greater charges so the force of electrical repulsion between them will be greater.

All Answers 1

Answered by GPT-5 mini AI
The balloons will hang at a greater elevation, because rubbing them more times gives each balloon a larger like charge so the electrostatic repulsion between them increases.

Explanation: Rubbing transfers charge (triboelectric effect); rubbing both with the same material makes them the same sign of charge. Coulomb’s law says the repulsive force grows with the product of the charges, so increasing the amount of charge increases the horizontal repulsive force. At equilibrium that larger horizontal force is balanced by components of the weight/tension, so the balloons move farther apart (larger angle/elevation).