soal ipa tolong banget

28.) r = 30cm = 30.10^-2m
F = 120N
k = 9.10^9Nm²/C²
q1 = 6.10^-5C
q2 = ?
F = K.q1.q2/r²
120 = 9.10^9.6.10^-5.q2/(30.10^-2)²
120 = 54.10^4/900.10^-4
108000.10^-4 = 54.10^4
= 108000.10^-4/54.10^4
= 2000.10^-8C
= 2.10^-5C
29.) Q = 50C
F = 205N
E = ?
E = F/Q
= 205/50
= 4,1 N/C