（1）對(duì)于正常工作的時(shí)鐘,時(shí)針的速度是30°/h=π/6(rad/h),分針的速度是360°/h=2π(rad/h),兩者速度差是330°/h=11π/6(rad/h).設(shè)兩者在1~2點(diǎn)間重合時(shí),時(shí)針與0點(diǎn)的夾角是a弧度,則分針轉(zhuǎn)過(guò)的弧度數(shù)就是2π+a,可見(jiàn)角程差是2π,那么按追趕問(wèn)題有
t=2π/(2π-π/6)=12/11h
所以a=(π/6)t=2π/11,2π+a=24π/11,此即分針跑過(guò)的弧度數(shù).
（2）1h55min=23/12h,時(shí)針走過(guò)的弧度數(shù)=π/6×23/12=23π/72,而處于π/2+23π/72=59π/72弧度處,
這時(shí)分針處在11點(diǎn)處,即-π/6弧度處,故時(shí)針與分針的夾角=59π/72+π/6=71π/72弧度,合177.5°