雷达二手表回收店

一辆汽车,加上货物重80000N,要迅速驶上长80m,高10m的斜坡,若摩擦阻力为5000N,则 汽车上坡时的牵引力至少为多大? 请提示我该怎么解答 一辆汽车的质量为10t,发动机的牵引力是5000N时汽车能在4min内沿斜坡匀速行驶500m若发动机的机械效率为60%发动机做的总功多大?汽车发动机做的有用功多大?汽车上升的高度多大?行驶时发动机 Go there to Wish you well. wish you well done everything什么意思 wish you well,i can not stay 的意思是? 有限小数属于哪种有理数啊.有限小数是正有理数？还是负有理数？是整数还是分数？ up to the present 是"to the present"还是"to present"? mon chéri.happy birthday!Wish You Safe And Well and wish you are happy everyday. 语法有无错?Up to the present,the scientists have been c时态有这样的挖、错的话帮忙改一下 I am free for a couple of hours. a couple hours 为什么不用 a couple of talk for hours 一只小瓶装满水后质量为88g,若在此瓶中放一质量为10g的小石子,水溢出后总质量为94g,求小石子的密度. l go there with your friends by train.提问go there 提问by train 同义句改写：1.We've only raised $2000 up to the present for the poor children.We've only raised $2000 up to the present for the poor children.We've only raised $2000 ______________for the poor children.I've been here for only two we WE USE IT FOR AN ACTION IN THE PAST LEADING UP TO THE PRESENT.中LEADING UP TO THE PRESENT couples of 和 a couple of 的区别要具体说明,最好有举例 a couple 英语.a couple of修饰可数还是不可数? 英语单词gr（）（）nb（）（）ns每空一个字母 A couple of months后边的谓语动词用单数还是复数,为什么? ▁ns▁de英语单词? 静止在地面上的一小物体,在竖直方向上的拉力作用下开始运动,再向上运动的过程中物体的机械能与位移静止在地面上的小物体,在竖直向上的拉力作用下由静止开始运动,在向上运动的过程中 一个物体受到竖直向上的拉力F=650N,由静止开始向上运动,物体在最初2S内的位移为6m,求物体的质量 根据首字母提示及释义完单词 1.e＿ at any time up to the perent at any any time ,at any time有区别吗 With the meeting ____in just a couple of hours ,I had n't the time to worry about those unimportant things A.BegunB.Beginning c.Would begin.D.To beginKey.A.Why 求讲解.With the meeting（ ） in just a couple of hours..With the meeting ____in just a couple of hours ,I hadn't the time to worry about those unimportant things.A.begunB.beginningC.would beginD.to begin With the meeting_in just a couple of hours,Ihadn't the time to worry aboutthose unimportant things.A.begun B.beginning C.would begin D.to begin 求翻译