14.
(2023高二上·常熟期中)
如图甲,将一小球用细绳悬挂于固定悬点O,将三高精度力传感器(不考虑质量)接在球与细线之间,小球静止悬停在A位置,一玩具枪在球左侧水平放置,枪口中心与球心等高。某时刻,玩具枪以一定初速度v
0发射质量为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3Cmn%3E.%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmtext%3Eg%3C%2Fmtext%3E%3C%2Fmath%3E)
的水弹,水弹跟小球碰撞后,立即散开(可认为速度为0)且碰撞时间很短可忽略,之后小球开始摆动,整个过程力传感器数据F随时间t变化的曲线如图乙所示,已知小球上摆的最大摆角θ很小,图中
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Et%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmsqrt%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsqrt%3E%3Cmtext%3E%CF%80%3C%2Fmtext%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3Cmtext%3Es%3C%2Fmtext%3E%3C%2Fmath%3E)
时刻为水弹与小球碰撞时刻,小球摆动过程中始终不与枪相撞,忽略空气阻力,当地重力加速度g取10m/s
2 , 求:
![](//tikupic.21cnjy.com/2023/12/20/63/e5/63e51767a084276e622907b3ea79888e_522x290.png)