如圖1示，用A、B兩*簧測力計拉橡皮條，使其伸長到O點（α+β＜）                      ...

問題詳情：

如圖1示，用A、B兩*簧測力計拉橡皮條，使其伸長到O點（α+β＜）                                                                                                                                     

（1）現保持A的讀數不變，而使夾角減小，適當調整*簧測力計B的拉力大小和方向，可使O點保持不變，這時B的示數FB和夾角β的變化應是                                                                                                 

A．FB一定變大，夾角β一定變大                          B．FB一定不變    夾角β一定變大                                                   

C．FB一定變小                                                      夾角β一定變小   D．FB變大、不變、變小均有可能   夾角β變小                                                                                                                      

（2）如圖2所示是*和乙兩位同學在做以上實驗時得到的結果，其中哪一個比較符合實驗事實？                                                                                                                                               

【回答】

（1）C；（2）*．

知識點：專題十三 中學物理實驗

題型：實驗,探究題