14.
(2022高三上·江西月考)
如图,水平面与倾斜传送带平滑连接,传送带倾角
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3E%CE%B8%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E37%3C%2Fmn%3E%3Cmo%3E%C2%B0%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
且以
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3Ev%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2.0%3C%2Fmn%3E%3Cmtext%3Em%2Fs%3C%2Fmtext%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的恒定速率顺时针旋转;水平面上c点左侧部分粗糙,c点右侧部分光滑。质量为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3Em%3C%2Fmi%3E%3Cmtext%3E%3D2kg%3C%2Fmtext%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的小滑块P与固定挡板间有一根劲度系数为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3Ek%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E200%3C%2Fmn%3E%3Cmtext%3EN%2Fm%3C%2Fmtext%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的轻弹簧(P与弹簧不拴接),初始时P放置在c点静止且弹簧处于原长。现给P施加一方向水平向左、大小为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmi%3EF%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E52%3C%2Fmn%3E%3Cmtext%3EN%3C%2Fmtext%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
的恒力,使P向左运动,当P速度为零时立即撤掉恒力,一段时间后P将滑上传送带。已知P与水平面粗糙部分的动摩擦因数为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3E%CE%BC%3C%2Fmi%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
, P与传送带间的动摩擦因数
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3E%CE%BC%3C%2Fmi%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.5%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
, 设最大静摩擦力等于滑动摩擦力,弹簧的形变在弹性限度内,弹簧的弹性势能表达式为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmsub%3E%3Cmi%3EE%3C%2Fmi%3E%3Cmtext%3EP%3C%2Fmtext%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmfrac%3E%3Cmi%3Ek%3C%2Fmi%3E%3Cmsup%3E%3Cmi%3Ex%3C%2Fmi%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsup%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
, x为弹簧的形变量,不计滑块滑上传送带时能量的损失,重力加速度
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi%3Eg%3C%2Fmi%3E%3C%2Fmath%3E)
取
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmrow%3E%3Cmtext%3E10m%2F%3C%2Fmtext%3E%3Cmsup%3E%3Cmtext%3Es%3C%2Fmtext%3E%3Cmtext%3E2%3C%2Fmtext%3E%3C%2Fmsup%3E%3C%2Fmrow%3E%3C%2Fmath%3E)
, 计空气阻力。
![](//tikupic.21cnjy.com/2022/10/21/80/9a/809acea8310ac4448c182fd136974d7f_416x130.png)