Two metal spheres are suspended from strings. The
charge on sphere (a) is -2.0*10^2 C and the other (b)-4.0
*10^-8 C. Use the diagram to help you find the electric
force acting on the spheres?
3.0 m

A. An attractive force of 24*10^3 N

B. A repulsive force of 8.0*10^3 N.

C. An attractive force of 8.0*10^3 N

D. A repulsive force of 24*10^3N

The answer to your question is the letter B. A repulsive force of 8.0 x 10³N

Explanation:

Data

Charge 1 = -2.0 x 10² C

Charge 2 = -4.0 x 10⁻⁸ C

K (Coulomb constant) = 9 x 10⁹ Nm²/C²

distance = 3 m

Formula

F = K (q₁ x q₂) / r²

Substitution

F = 9 x 10⁹ (-2.0 x 10²)(-4.0 x 10⁻⁸) / 3²

Simplification

F = 9 x 10⁹ (0.000008) / 9

F = 72000 / 9

Result

F = 8000 C = 8 x 10³ N

Conclusion

As both spheres are negative the force is negative with magnitude 8x 10³N

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