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Charges (-e) on electron and (e) on proton exert a force of attraction given by

1. Force = (K)(-e)(e) / r²
2. Force = -Ke² / r³
3. Force = K(e² / r²)
4. Force = -Ke² / r³ (r̂)

Correct answer: Force = K(e² / r²)

Solution

The force between two charges is given by Coulomb's law: F = K(q1)(q2)/r². Substituting q1 = -e and q2 = e, the magnitude of the force becomes K(e²/r²). The negative sign is not included in the magnitude.

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