Question

Какие заряд должны быть у двух одинаковых шариков чтобы они подтягивались с силой 5 мН находясь на расстоянии 20 см друг от друга

Answer 1

F=k*q^2/R^2
q=sqrt(F*R^2/k)=sqrt(5*10^-3*0,04/9*10^9)=1,5*10^-7 Кл

Answer 2

Calculating the Electric Force Between Two Spheres

To calculate the electric force between two spheres, we can use Coulomb's law, which states that the force between two point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between their centers. The formula for the electric force between two point charges is given by:

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

Where: - F is the magnitude of the force between the charges, - k is Coulomb's constant, approximately equal to 8.9875 x 10^9 N m^2/C^2, - q1 and q2 are the magnitudes of the charges, and - r is the distance between the centers of the charges.

Applying the Formula to the Given Scenario

In this case, we are dealing with two identical spheres, so the charges on each sphere will be the same. Let's assume the charges on each sphere are denoted by q. The force between the spheres is given as 5 mN (millinewtons), and the distance between them is 20 cm (0.2 m).

Using Coulomb's law, we can rearrange the formula to solve for the charge q:

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

Substituting the given values: - F = 5 mN = 5 x 10^-3 N - r = 0.2 m - k = 8.9875 x 10^9 N m^2/C^2

We can now calculate the value of q using the given values and the formula.

Calculation

q = sqrt((5 x 10^-3 N * (0.2 m)^2) / (8.9875 x 10^9 N m^2/C^2))

q ≈ 3.162 x 10^-7 C

Therefore, the magnitude of the charge on each sphere should be approximately 3.162 x 10^-7 C for them to exert a force of 5 mN on each other at a distance of 20 cm.