题型:选择题 —__________? —Quite well, thanks.[ ]A. What do you do? B. What do you think of it?C. How are you getting on with your math ?D. Are you quite good at English? 查看答案
题型:填空题 用200 N的拉力将地面上一个质量为10 kg的物体提升10 m(重力加速度 g =" 10" m/s2,空气阻力忽略不计)。拉力对物体所做的功是_________J;物体被提高后具有的重力势能是_________J(以地面为零势能参考面)。 查看答案