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Each of two small non-conducting spheres is charged positively, the combined charge being 40 μC. When the two spheres are 50 cm apart, each sphere is repelled from the other by a force of magnitude 2.0 N. Determine the magnitude of the smaller of the two charges.

Respuesta :

Answer:

1.44 x 10⁻⁶ C

Explanation:

[tex]q_{1}[/tex] = charge on one sphere

[tex]q_{2}[/tex] = charge on other sphere

[tex]q[/tex] = Total charge on the two spheres = 40 μC

[tex]q_{1}+ q_{2}[/tex] = [tex]q[/tex]

[tex]q_{1}+ q_{2}[/tex] = 40 x 10⁻⁶

[tex]q_{1}[/tex] = (40 x 10⁻⁶) - [tex]q_{2}[/tex]                                   eq-1

[tex]r[/tex] = distance between the two spheres = 50 cm = 0.50 m

[tex]F[/tex] = magnitude of force between the two spheres = 2.0 N

Magnitude of force between the two spheres is given as

[tex]F = \frac{k q_{1} q_{2}}{r^{2}}[/tex]

[tex]2.0 = \frac{(9\times 10^{9}) ((40\times 10^{-6}) - q_{2}) q_{2}}{0.50^{2}}[/tex]

[tex]q_{2}[/tex] = 1.44 x 10⁻⁶ C

This question involves the concept of Colomb's Law.

The magnitude of the smaller charge is "1.4 μC".

Colomb's Law

According to Colomb's Law:

[tex]F=\frac{Gm_1m_2}{r^2}[/tex]

where,

  • F = Force = 2 N
  • K = Colomb's constant = 9 x 10⁹ N.m²/C²
  • q₁ = charge of first sphere
  • q₂ = charge of second sphere
  • r = distance between spheres = 50 cm = 0.5 m

Therefore,

[tex]2\ N = \frac{(9\ x\ 10^{9}\ N.m^2/C^2)q_1q_2}{(0.5\ m)^2}\\\\q_1q_2=5.55\ x\ 10^{-11}\ C^2\\\\q_1=\frac{5.55\ x\ 10^{-11}\ C^2}{q_2}\ ----------- eqn (1)[/tex]

The combined charge is given as:

[tex]q_1+q_2= 40\mu C \\q_1+q_2= 4\ x\ 10^{-5}\ C[/tex]

using eqn (1):

[tex]\frac{5.55\ x\ 10^{-11}\ C^2}{q_2} + q_2 = = 4\ x\ 10^{-5}\ C\\\\q_2^2-(4\ x\ 10^{-5})q_2+5.55\ x\ 10^{-11}=0[/tex]

solving this quadratic equation, we get:

q₂ = 38.5 x 10⁻⁶ C = 38.5 μC

(OR)

q₂ = 1.4 x 10⁻⁶ C = 1.4 μC

Using these values in eqn (1):

[tex]q_1=\frac{5.55\ x\ 10^{-11}\ C^2}{38.5\ x\ 10^{-6}\ C}\ (OR)\ q_1=\frac{5.55\ x\ 10^{-11}\ C^2}{1.4\ x\ 10^{-6}\ C}\\\\q_1=1.4\ x\ ^{-6}\ C = 1.4\ \mu C\ (OR)\ q_1=39\ x\ 10^{-6}\ C = 39\ \mu C[/tex]

Hence, the smaller charge is 1.4 μC.

Learn more about Colomb's Law here:

https://brainly.com/question/506926