23. 在一以等加速度a上升之電梯內，有一斜角α斜面長s之光滑面。則物體自光滑斜面頂端沿斜面下滑至斜面底端需時若干？

6. Given that the enthalpy required to convert CHCl3(g) to gaseous C, H, and Cl atoms is 1397 kJ/mol and that the dissociation enthalpy of a C-H bond is 413 kJ/mol, what is the bond dissociation enthalpy of a C-Cl bond？ (A)328 kJ/mol　(B)603 kJ/mol　(C)984 kJ/mol　(D)1397 kJ/mol