试题与答案

如图所示,光滑水平面上,水平恒力F拉小车和木块一起做匀加速直线运动,小车质量为M

题型:多选题

题目:

如图所示,光滑水平面上,水平恒力F拉小车和木块一起做匀加速直线运动,小车质量为M,木块质量为m,它们的共同加速度为,木块与小车间的动摩擦因数为μ。则在运动过程中

[ ]

A.木块受到的摩擦力大小一定为

B.木块受到的合力大小为

C.小车受到的摩擦力大小为

D.小车受到的合力大小为

答案:

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What would life be like without rich, creamy, mouthwatering, melt-in-your-mouth chocolate?

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However, for the African children who toil under slavelike conditions on cacao plantations, life is not sweet. The cacao bean is the main ingredient in the chocolate. According to a 2002 survey by the International Institute of Tropical Agriculture and the US Agency for International Development, about 284,000 children work in dangerous conditions on cacao farms in western Africa.

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