“初中物理机械效率”一节中提到,在总功一定的情况下,当有用功越大时,机械效率就越大。类比于我们的教学,在上课时间一定的情况下,只有当我们把这些有限的时间转化成有用的越多,效率才会越大,学生获得的也就越多,我们的课堂也就越高效。这就要求我们注重课堂教学有效的问题了。提高课堂教学效率是每一位教师孜孜追求的目标。 “Junior high school physics and mechanical efficiency ” section mentioned in the total work of a certain circumstances, when more useful work, the greater the mechanical efficiency. Analogous to our teaching, under certain circumstances of class time, the greater the efficiency, the more students gain, the more efficient our classes will be if we translate these finite times into useful ones . This requires that we pay attention to the problem of effective classroom teaching. Improve the efficiency of classroom teaching is every diligently pursue the goal.