《基础物理实验Ⅱ》课程实验报告

《基础物理实验Ⅱ》课程实验报告学院：理工院专业：光信息年级：2013级实验人姓名（学号）：吴俊宏（13342074）参加人姓名（学号）：王骥（133420）日期：2014年10月14日星期二下午测量扭摆在自由状态下的固有振动频率，并测量自由状态下的阻尼系数β初始振幅A0(°周期数n时间t=nT(s)末振幅An(°阻尼系数β=固有振动频率ωβ50558.06410.0246217053.89783543.9654973843.9404225267.78410.0255078334.0381173947.6940.50.0274019554.0853879367.97410.0248997413.9418511078.13400.0274469313.864295081608.04500.0226768113.9075193513.9153476688.02490.0252524023.9172792177.98500.0228473133.9368991968.04510.0202137973.9075058338.04490.0251895853.907534741结论：随着初始角度的增大，阻尼系数减小观察阻尼振动现象，测量阻尼系数与阻尼电压的变化关系阻尼电压U(V)阻尼电流I（A）初始振幅A0(°周期数n时间t(s)末振幅An(°阻尼系数β005057.91410.02508861410.58.02390.03098021920.0847.95390.03125300130.1278.01370.03759114840.1707.88290.06912781450.2147.71260.08481536560.2577.91270.07789963870.3007.84230.09904703980.3427.78200.11777515890.3857.64170.141205453100.4277.84130.171820618测量调速旋钮位置与简谐驱动力矩频率之间的变化关系旋钮转动圈数周期数n时间t（s）频率ω(s-1057.454.2169028910．57.514384.2569006151.56.764.64732641127.634.1174215642.57.684.09061543437.684.0906154343.57.93.97669956247.774.0432337884.57.953.95168887257.883.9867927085.58.053.9025995768.213.8265440366.58.33.7850513978.23.8312105537.58.633.64031593788.383.7489172488.58.653.63189902198.643.6361026089.58.823.561896433观察共振现象U=7Vβ=圈数n频率ω振幅A（°）相位差（rad）φ=（且因为相位差总是落后，若求得大于0，减去π）04.21690289120-2.7868744210．542.74384065914.25690061525.5-2.827316121.54.64732641129-2.9910919524.11742156433.5-2.6221041622.54.09061543439-2.55004564234.09061543447-2.5500456423.53.97669956258-1.92040941344.04323378873-2.3684455254.53.951688872100-1.68389688153.986792708124.5-2.0064162385.53.90259957105-1.20440350563.826544036103-0.708548756.53.7850513986-0.5583590373.83121055372-0.7295903347.53.64031593754-0.30695554283.74891724851-0.4670988888.53.63189902145-0.29873933793.63610260839-0.302791249.53.56189643335-0.243531396结论：由图知得共振频率大于固有频率，与理论不符。（解释：在小于固有频率处，有真实共振频率未测得）【思考题】实验过程中如何设置实验设备，使波尔振动仪产生自由振动，阻尼振动，受迫振动。试讨论扭摆建立稳定的受迫振动过程的动力学过程。答：关闭阻尼电源，关闭周期性外力电机，波尔振动仪可产生自由振动。打开阻尼电源，关闭周期性外力电机，波尔振动仪可产生阻尼振动。打开阻尼电源，打开