Câu 1.
Lực tương tác giữa chúng:
\(F=k.\dfrac{\left|q_1q_2\right|}{r^2}=1,5\cdot10^{-3}\)\(\Rightarrow r^2=\dfrac{1,5\cdot10^{-3}}{9\cdot10^9\cdot\left|-3\cdot10^{-8}\cdot8\cdot10^{-8}\right|}=\dfrac{625}{9}\Rightarrow r=\dfrac{25}{3}m\)
Câu 2.
a)\(I=\dfrac{U}{R}=\dfrac{20}{10}=2A\)
\(U=IR=10\cdot2=20V\)
b)\(P=U\cdot I=20\cdot2=40W\)
c)\(Q=RI^2t=10\cdot2^2\cdot10\cdot60=24000J\)