《基礎物理實驗Ⅱ》課程實驗報告

《基礎物理實驗Ⅱ》課程實驗報告學院：理工院專業(yè)：光信息年級：2013級實驗人姓名（學號）：吳俊宏（13342074）參加人姓名（學號）：王驥（133420）日期：2014年10月14日星期二下午測量扭擺在自由狀態(tài)下的固有振動頻率，并測量自由狀態(tài)下的阻尼系數(shù)β初始振幅A0(°周期數(shù)n時間t=nT(s)末振幅An(°阻尼系數(shù)β=固有振動頻率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結論：隨著初始角度的增大，阻尼系數(shù)減小觀察阻尼振動現(xiàn)象，測量阻尼系數(shù)與阻尼電壓的變化關系阻尼電壓U(V)阻尼電流I（A）初始振幅A0(°周期數(shù)n時間t(s)末振幅An(°阻尼系數(shù)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測量調速旋鈕位置與簡諧驅動力矩頻率之間的變化關系旋鈕轉動圈數(shù)周期數(shù)n時間t（s）頻率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觀察共振現(xiàn)象U=7Vβ=圈數(shù)n頻率ω振幅A（°）相位差（rad）φ=（且因為相位差總是落后，若求得大于0，減去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結論：由圖知得共振頻率大于固有頻率，與理論不符。（解釋：在小于固有頻率處，有真實共振頻率未測得）【思考題】實驗過程中如何設置實驗設備，使波爾振動儀產生自由振動，阻尼振動，受迫振動。試討論扭擺建立穩(wěn)定的受迫振動過程的動力學過程。答：關閉阻尼電源，關閉周期性外力電機，波爾振動儀可產生自由振動。打開阻尼電源，關閉周期性外力電機，波爾振動儀可產生阻尼振動。打開阻尼電源，打開