A:宇航员A处于平衡状态
B:宇航员A所受地球引力与他在地面上所受重力相等
C:宇航员A与“地面”B之间无弹力作用
D:若宇航员A将手中一小球无初速(相对于空间舱)释放,该小球将落到“地面”B
There was a time ______ I thought my dad didn't know a thing about being a good father.
计算质量为10 千克的物体所受到的重力,下列各等式中正确的是( )