ta có [tex]r_n=n^2.r_0\Rightarrow \left\{\begin{matrix} r_1=4^2.r_0=16r_0 & & \\ r_2=2^2.r_0=4r_0 & & \end{matrix}\right.[/tex]
Mà [tex]F_d=F_{ht}[/tex]
[tex]\Leftrightarrow \left\{\begin{matrix} k.\frac{\left | q.(-q) \right |}{r_1^2}=m.\frac{v_1^2}{r_1} & & \\ k.\frac{\left | q.(-q) \right |}{r_2^2}=m.\frac{v_2^2}{r_2} & & \end{matrix}\right. \Leftrightarrow \left\{\begin{matrix} k.\frac{\left | q.(-q) \right |}{(16r_0)^2}=m.\frac{v_1^2}{16r_0} & & \\ k.\frac{\left | q.(-q) \right |}{(4r_0)^2}=m.\frac{v_2^2}{4r_0} & & \end{matrix}\right.\Rightarrow \frac{v_1}{v_2}=...[/tex] (1)
Lại có [tex]v=\omega .r=\frac{2\pi }{T}.r\Rightarrow T=\frac{2\pi .r}{v}[/tex]
thay vào (1) tìm đc tỉ số [tex]\frac{T_1}{T_2}[/tex]