大学物理实验报告实验3三线摆报告

三线摆实验报告林一仙一、实验目的1、掌握水平调节与时间测量方法；2、掌握三线摆测定物体转动惯量的方法；3、掌握利用公式法测这定物体的转动惯量。二、实验仪器三线摆装置电子秒表卡尺米尺三、实验原理水平器1、三线摆法测定物体的转动惯量机械能守恒定律：Imgh12020简谐振动：2sint0T2dtT2d0costT2通过平衡位置的瞬时角速度的大小为：；00T2210Imgh2所以有：T0BCBC2121可以得到：hBCBC根据图BCBC1!BC2AB2AC2l2Rr2从图2可以看到：AC2R2r22Rrcos0根据余弦定律可得11BCABAC2l2R2r22Rrcos所以有：2211110整理后可得：4Rrsin202h2Rr(1cos)0BCBCBCBC11BCBC2H；摆角很小时有：sin(2)0021Rr20h所以：2HmgRrba；又因，I整理得：0TRr24H332mgabI所以：0T212H2若其上放置圆环，并且使其转轴与悬盘中心重合，重新测出摆动周期为1T和H则：1(mM)gabI1T2112H21待测物的转动惯量为：I=I1-I02、公式法测定物体的转动惯量圆环的转动惯量为：1D2DIM2281四、实验内容1、三线摆法测定圆环绕中心轴的转动惯量a、用卡尺分别测定b、调节三线摆的悬c、调节三线摆d、用米尺测定悬盘到上盘e、让悬盘稳定不摇晃。）；三线摆上下盘悬挂点间的距离a、b（三个边各测一次再平均）；线使悬盘到上盘之间的距离H大约50cm多；地脚螺丝使上盘水平后再调节三线摆悬线的长度使悬盘水平；三线接点的距离H；静止后轻拨上盘使悬盘作小角度摆动（注意观察其摆幅是否小于10度，摆动是否f、用电子秒表测定50个摆动周期的摆动的时间t；g、把待测圆环置于悬盘上（圆环中心必须与悬盘中心重合）再测定悬盘到三线与上盘接点间的距离H，重复步骤e、f。12、公式法测定圆环绕中心轴的转动惯量用卡尺分别测定圆环的内径和外径，根据上表中圆环绕中心轴的转动惯量计算公式确定其转动惯量测定结果。（圆环质量见标称值）五、数据处理表一三线摆法项目a(cm)b(cm)H(cm)t(s)123456平均值4.29511.31149.6386.0249.994.28011.29649.5585.7250.1094.354.31011.32449.5886.1949.8092.884.29411.31449.6086.3150.0094.3649.7085.6049.9095.2249.6086.0450.0595.3049.7586.2750.1094.88H1(cm)t1(s)表二公式法项目123456平均值D(cm)12.18212.17812.16012.18012.17612.184d(cm)10.17810.16010.14210.18610.18010.13410.163m=299g;M=543gaa33a2i4.295cm;saiai10.015i13130.00220.0152musa20.015233a33bbb2i11.311cm;sbibi10.015i13130.00220.0152musb20.015233b66HHi2Hi49.63cm;sHi10.078i1616Hm0.0520.0842usH20.078233H2tt66tisiti186.02s;0.3i1616t0.0520.0422must2t0.0323366HHH2111iH1i49.99cm;s0.12i1i1616H10.0520.132mus2H10.12233H166ttt21i94.50s;st111it10.9i1i1616t92.8894.500.91.7392.96,剔除之后重新计算平均值：1255tt2t'''1i11it'94.82s;st1'i1i150.465110.0520.462must12t10.46233mgabT2mgabt22999804.29511.31186.0220.717510422.421104I0122H122H502123.1449.635022mM)gabT(299543)9804.29511.31194.50(21I2123.1449.99502122H11III(2.4210.7175)1041.704104gcm201uuuu2222E2abtHabtHI00.0150.01520.0420.08422224.29511.31186.0249.631.221051.81069.7621042.9106101043.2%uuuu2222EI12tHab11abtH110.0150.01520.460.1322224.29511.31194.8249.991.221051.81069.4141056.810611.501050.11%uIE07.71751033.2%0.025104I0I0uIE2.421100.11%0.00310441I1I1uu2u20.02520.00321040.03104I1II0u0.03104E1.7041041.8%III1u1.700.03104gcm2I1.8%IIEI66DiDD2i12.177cm;sDDi10.009i1616D12.16012.1770.0091.7312.162,剔除之后重新计算平均值：355D'D'D'2ii0.0032D'i112.180cm;sD'i151566ddd2i10.163cm;sdidi10.022i161611IM(D2d2)543(12.180210.1632)1.7080104g·cm2880.00220.00342msuD20.0032233D0.00220.00252msud2d0.0022233uD2D2uD；u2uD20.003412.1800.083D2D2Dud2d2u；u2ud20.002510.1630.051dd2d2duu2u20.08320.05120.1DdD2d222uEuu241022D2d240.08320.051212.180210.16320.12D2d2Dd251.64D2d2IuEI41041.70801047IIu1.70800.0007104gcm2I0.04%IIEI另一种型号（大盘）表一公式法项目123456平均值8.65317.27950.8276.9451.0584.34a(cm)b(cm)H(cm)t(s)8.63617.26450.9077.0651.0584.538.62617.37450.8076.8551.1584.638.69817.20050.7076.9751.1084.8850.8576.6951.0085.2850.9076.8150.9584.7550.8077.2551.0584.34H1(cm)t1(s)表二公式法项目123456平均值19.01416.973D(cm)d(cm)19.02216.940M=400g19.01816.96219.00417.02019.02816.96618.98816.98619.02616.966m=395g;3aaa32i8.653cm;saiai10.0390.039i1313m20.0022usa20.039233a33bbb2i17.279cm;sbibi10.088i13130.00220.0882musb20.0882b3366HHi2Hi50.82cm;sHi160.076i161H0.0520.0822musH20.076233Htt66t2is76.94s;iti160.2i161t20.052must20.22t0.23366HHH2111iH1i51.05cm;s0.071i1i1616H10.0520.0772mus2H10.071233H166ttt21i84.74s;st111it10.33i1i16160.0520.0.342must120.332t133mgabT2mgabt23959808.65317.27976.9422.27910425.540104I0122H122H502123.1450.825022mM)gabT(395400)9808.65317.27984.74(21I2123.1451.05502122H11III(5.5402.279)1043.261104gcm201uuuu2222E2abtHabtHI00.0390.08820.20.08222228.65317.27976.9450.822.031052.601052.711052.611060.7611040.9%uuuu2222EI12tHab11abtH110.0390.08820.340.07722228.65317.27984.7451.052.031052.601056.441052.310611.31051.1%uIE02.2791040.9%0.021104I0I0uIE5.540101.1%0.06110441I1I1uu2u20.02120.06121040.07104I1II0u0.07104E3.2611042.2%III13.260.07104gcm2IIuIE2.1%I66DiDD2i19.014cm;sDDi10.016i161666ddd2i16.973cm