Đáp án:
Tốc độ góc kim giờ là:
\({\omega _h} = \dfrac{{2\pi }}{{{T_h}}} = \dfrac{{2\pi }}{{12.3600}} = \dfrac{\pi }{{21600}}\)
Tốc độ góc kim phút là:
\({\omega _{ph}} = \dfrac{{2\pi }}{{{T_{ph}}}} = \dfrac{{2\pi }}{{3600}} = \dfrac{\pi }{{1800}}\)
Tốc độ góc kim giây là:
\({\omega _s} = \dfrac{{2\pi }}{{{T_s}}} = \dfrac{{2\pi }}{1} = 2\pi \)
Ta có:
\(\begin{array}{l}
\dfrac{{{\omega _h}}}{{{\omega _{ph}}}} = \dfrac{1}{{12}}\\
\dfrac{{{\omega _h}}}{{{\omega _s}}} = \dfrac{1}{{21600}}\\
\dfrac{{{\omega _{ph}}}}{{{\omega _s}}} = \dfrac{1}{{1800}}
\end{array}\)
Mặt khác:
\(\dfrac{{{v_h}}}{{{v_{ph}}}} = \dfrac{{{\omega _h}}}{{{\omega _{ph}}}}.\dfrac{{{R_h}}}{{{R_{ph}}}} = \dfrac{1}{{12}}.\dfrac{1}{2} = \dfrac{1}{{24}}\)
\(\dfrac{{{v_h}}}{{{v_s}}} = \dfrac{{{\omega _h}}}{{{\omega _s}}}.\dfrac{{{R_h}}}{{{R_s}}} = \dfrac{1}{{21600}}.\dfrac{1}{2}.\dfrac{3}{4} = \dfrac{1}{{57600}}\)
\(\dfrac{{{v_{ph}}}}{{{v_s}}} = \dfrac{{{\omega _{ph}}}}{{{\omega _s}}}.\dfrac{{{R_{ph}}}}{{{R_s}}} = \dfrac{1}{{1800}}.\dfrac{3}{4} = \dfrac{1}{{2400}}\)
