What is the force, in terms of Coulomb's constant, between two electrical charges of 6 C6C and -6 C6C that are 12 m 12m apart?

1 Answer
Jun 3, 2017

F = -1/4k_eF=14ke

Explanation:

The electric force FF between two point charges q_1q1 and q_2q2 a distance rr apart is given by the equation

F =k_e(q_1q_2)/(r^2)F=keq1q2r2

where k_eke is Coulomb's constant, equal to 8.988 xx 10^9 ("N • m"^2)/("C"^2)8.988×109N ∙ m2C2

Plugging in known values, we have

F =k_e((6"C")(-6"C"))/((12"m")^2)F=ke(6C)(6C)(12m)2

= k_e(-36"C"^2)/(144"m"^2)=ke36C2144m2

= -(1"C"^2)/(4"m"^2)k_e=1C24m2ke

So, in terms of Coulomb's constant (k_eke), the (attractive) electric force acting between the two point charges is

color(red)(F = -1/4k_e)F=14ke

(excluding units)