Question

Небольшие одинаковые по размеру металлические шарики, заряды которых 20 нкл и 60 нкл удерживают на расстоянии 20 см. Шарики перевели в соприкосновение и отвели на то же самое расстояние. Каким было и каким стало взаимодействие шариков??

Answer 1

Заряды станут одинаковые и согласно закону сохранения электрического заряда q=(q1+q2)/2=(60+20)/2=40 нКл
F=k*q^2/R^2=9*10^9*1600*10^-18/400*10^-4=36*10^-5 Н

Answer 2

Interaction between the Metal Balls

When the metal balls are initially separated by a distance of 20 cm, with charges of 20 nC and 60 nC, they experience an interaction due to the electric force between them. To determine how the interaction changes when the balls are brought into contact and then separated again, we need to consider the properties of electric charges.

Electric Charges and their Interactions

Electric charges can be positive or negative. Like charges (both positive or both negative) repel each other, while opposite charges (one positive and one negative) attract each other. The strength of the electric force between two charges depends on their magnitudes and the distance between them.

Initial Interaction

Initially, the two metal balls have charges of 20 nC and 60 nC, respectively, and are separated by a distance of 20 cm. The interaction between them is determined by the electric force. The force between two charges can be calculated using Coulomb's Law:

F = k * (q1 * q2) / r^2

Where: - F is the electric force between the charges, - k is the electrostatic constant (approximately 9 × 10^9 N m^2/C^2), - q1 and q2 are the magnitudes of the charges, and - r is the distance between the charges.

To determine how the interaction changes, we need to compare the initial force with the force after the balls are brought into contact and then separated again.

After Contact

When the metal balls are brought into contact, electrons can flow between them, equalizing their charges. Since the charge on one ball is 20 nC and the charge on the other ball is 60 nC, electrons will flow from the ball with the higher charge to the ball with the lower charge until both balls have the same charge.

After contact, both balls will have the same charge, which is the average of their initial charges. The average charge can be calculated as:

Average charge = (q1 + q2) / 2

In this case, the average charge will be (20 nC + 60 nC) / 2 = 40 nC.

After Separation

After the balls are separated again, they will repel each other due to their like charges. The force between them will depend on their new charges and the distance between them.

Since both balls now have the same charge of 40 nC, we can use Coulomb's Law to calculate the force between them. However, the distance between the balls after separation is not provided in the question. Therefore, we cannot determine the exact force without this information.

Conclusion

In summary, when the metal balls with charges of 20 nC and 60 nC are initially separated by a distance of 20 cm, they experience an interaction due to the electric force between them. After being brought into contact, the balls will have the same charge of 40 nC. However, without the information about the distance between the balls after separation, we cannot determine the exact force between them.