Question

1. In the video, the students discussed with the professor how objects can become charged through contact interactions at the microscopic level. Which of the following could possibly happen when two neutral objects are rubbed together? There may be more than one possibility.
A. Chemical bonds can break in such a way that atoms in the objects can gain or lose electrons. One object can gain electrons overall, with the electrons coming from the other object. The two objects thereby end up with opposite net charges.
B. Rubbing imparts energy to the two objects, allowing them to create excess electrons and thereby allowing both to have a net negative charge after contact.
C. Friction between the two objects can destroy electrons in them, allowing both to have a net positive charge after contact There might not be any changes to the chemical bonds between atoms, and the two objects remain neutral after contact.
2. In the video, the professor demonstrated the use of a sensor that allows the determination of the sign of the charge of an object. Previously, the students in the video had created two types of charged sticky tape,"pointy tape and square tape. Using the charge sensor, what did the students find about the sign of the charge on these two different tapes?
A. Both the pointy and the square tapes had a net negative charge.
B. The pointy tape had a net negative charge, and the square tape had a net positive charge.
C. Both the pointy and the square tapes had a net positive charge.
D. The pointy tape had a net positive charge, and the square tape had a net negative charge.
3. Suppose the students in the video have a piece of pointy tape, and they bring it near some object that they had rubbed with fur. They observe the pointy tape being repelled from this object. What can they conclude about the charge of the object?
A. It has the opposite sign of charge as the pointy tape.
B. It has the same sign of charge as the pointy tape.
C. Nothing can be concluded about the charge of the object.

Answer 1

Answer:

1.) A

2.) B

3.) B

Explanation:

1.) A. Chemical bonds can break in such a way that atoms in the objects can gain or lose electrons. One object can gain electrons overall, with the electrons coming from the other object. The two objects thereby end up with opposite net charges. 

2.) The pointy tape had a net negative charge, and the square tape had a net positive charge.

3.) Any object rubbed with fur will gain electron and become a negative charged object.

Since the pointy tape being repelled from this object, and like charges repel each other according to the law of Electrostatic, they can conclude that the charge of the object has the same sign of charge as the pointy tape.