题目
如图,菱形ABCD的对角线AC=4cm,把它沿着对角线AC方向平移1cm,得到菱形EFGH,则图中阴影部分图形的面积与四边形EMCN的面积之比为········································································· ( ) A.4∶3 B.3∶2 C.14∶9 D.17∶9一重球用细绳悬挂在匀速前进中的车厢天花板上,当车厢突然制动时,则( )
A.绳的拉力突然变小
B.绳的拉力突然变大
C.绳的拉力没有变化
D.无法判断拉力有何变化