Question

Помогите, пожалуйста, очень надо! Наэлектризованный маленький шарик был приведен в соприкосновение с равным ему ненаэлектризованным. Помещенные затем на расстоянии r = 9 см шарики отталкиваются с силой F = 0,25 мН. Каков был первоначальный заряд шарика?

Answer 1

Из формулы закона Кулона найдем заряд шариков: F = k·q²/r² ⇒ q = √F·r²/k =
= r·√F/k = 9·10^-2·√0,25·10^-3/9·10^9 = 1,5·10^-8 Кл. 
первоначальный заряд одного шарика был 3·10:-8 Кл.

Answer 2

Calculation of the Initial Charge of the Ball

To determine the initial charge of the ball, we can use Coulomb's law, which states that the force between two charged objects is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.

The formula for Coulomb's law is:

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

Where: - F is the force between the two objects - k is the electrostatic constant (approximately 9 x 10^9 Nm^2/C^2) - q1 and q2 are the charges of the two objects - r is the distance between the centers of the two objects

In this case, we have two balls with the same size and opposite charges. When they are brought into contact, they will share their charges equally. Let's assume the initial charge of each ball is q.

After contact, the two balls will have charges of +q and -q. When they are placed at a distance of 9 cm (0.09 m) from each other, they repel each other with a force of 0.25 mN (0.25 x 10^-3 N).

Using Coulomb's law, we can set up the equation:

F = k * (q * (-q)) / r^2

Simplifying the equation, we get:

0.25 x 10^-3 N = (9 x 10^9 Nm^2/C^2) * (q^2) / (0.09 m)^2

Solving for q, we find:

q^2 = (0.25 x 10^-3 N * (0.09 m)^2) / (9 x 10^9 Nm^2/C^2)

q^2 = 0.0025 C

Taking the square root of both sides, we get:

q = 0.05 C

Therefore, the initial charge of the ball was 0.05 Coulombs.