问题 问答题

(1)经过多长时问两物体在车上相遇?

(2)若在相遇瞬问撤去推力,则和小车最终速度各为多大?

(3)两物体相遇前,系统因摩擦产生的总热量是多少?

答案

(1)0.4s (2) 1.8m/s (3)0.4864J

(1)作用后,均做匀加速直线运动

                                                 (1分)

                                                (1分)

                                                                 (1分)

设经时间相遇,相遇时                                        (1分)

   解得                        (1分)

(2)相遇前                                                                     (1分)

    (1分)          (1分)

最终相对静止,撤去后系统

                                           (1分)

(3)             (1分)                (1分)

        (1分)                             (1分)

(1分)                     (1分)

    (1分)        (1分)

                                                                         (1分)

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