挑战习题
1/5单选题
难度:

1.小明用如图所示的滑轮组,将重为1.5N的物体匀速提升到一定高度,在此过程中,手拉力的大小实际应该是(  )
A 小于0.75N
B 等于0.75N
C 大于0.75N
D 等于0.5N
提示1:
IOayoeacieivtOW/veeVpee7s+mHjeWPiuaRqeaTpg==
提示2:
IOWcqOS4jeiAg+iZkee7s+mHjeWPiuaRqeaTpueahOaDheWGteS4i++8jOaLieWKm+etieS6jjAuNzVO
提示3:
IOeOsOWunuS4re+8jOe7s+WtkOi/mOWPl+WIsOaRqeaTpuWKm++8jOaJgOacieWkp+S6jjAuNzVO
正确答案:Qw==
PGRpdj7lnKjmj5DljYfph43niannmoTov4fnqIvkuK3vvIzmi4nlipvkuI3kvYbmj5DnnYDniankvZPvvIzov5jmj5DnnYDliqjmu5Hova7vvIzov5jopoHlhYvmnI3nu7PlrZDlkozmu5Hova7pl7TnmoTmkanmk6blipvvvIzmiYDku6U8aW1nIHdpZHRoPTQzIGhlaWdodD00MiBzcmM9Imh0dHBzOi8vcDEucWluZ2d1by5jb20vRzEvTTAwLzAwLzgzL3JCQUNGRk1NWXZ6RDdlLXZBQUFCd1dCaUNEWTc3NS5wbmciPuOAgjwvZGl2Pg==