Answer:
0.00264 C
Step-by-step explanation:
From Coulomb's law,
F = kqq'/r²........................ Equation 1
Where F = Force of attraction, k = coulombs constant, q = second charge, q' = First charge.
make q the subject of the equation
q = Fr²/kq'.................... Equation 2
Given: F = 19 N, r = 25 m, q = 0.0005 C, k = 9×10⁹ Nm²/C²
q = 19×25²/(0.0005×9×10⁹)
q = 11875/4500000
q = 0.00264 C
Hence the magnitude of the second charge = 0.00264 C