Question

如圖為利用氣墊導軌（滑塊在該導軌上運動時所受阻力可忽略）“驗證機械能守恒定律”的實驗裝置，完成以下填空．                                                                                                                 

                                           

實驗步驟如下：                                                                                                               

①將氣墊導軌放在水平桌面上，桌面高度不低于1m，將導軌調(diào)至水平．                                           

②測出擋光條的寬度l和兩光電門中心之間的距離s．                                                          

③將滑塊移至光電門1左側(cè)某處，待砝碼靜止不動時，釋放滑塊，要求砝碼落地前擋光條已通過光電門2．                                                                                              

④讀出滑塊分別通過光電門1和光電門2時的擋光時間△t₁和△t₂．                                            

⑤用天平稱出滑塊和擋光條的總質(zhì)量M，再稱出托盤和砝碼的總質(zhì)量m．                                         

⑥滑塊通過光電門1和光電門2時，可以確定系統(tǒng)（包括滑塊、擋光條、托盤和砝碼）的總動能分別為E_k1=           和E_k2=                                                                                                     ．

⑦在滑塊從光電門1運動到光電門2的過程中，系統(tǒng)勢能的減少△E_p=                              ．（重力加速度為g）             

⑧如果滿足關(guān)系式                                                                           ，則可認為驗證了機械能守恒定律．        

                                                                                                                                       

Answer 1

（1），（

（2）△E_p=mgs 

（3）△E_p=E_k2﹣E_k1