| ||
3 |
| ||
6 |
| ||
3 |
| ||
6 |
A.C球重力
| B.C球重力
| ||||||
C.杆对A球支持力(2+2
| D.杆对B球支持力(2+
|
A.若AB杆计重力,而BC杆不计重力时,由B指向C |
B.若AB杆计重力,而BC杆不计重力时,由C指向B |
C.若AB杆不计重力,而BC杆计重力时,由B指向A |
D.若AB杆不计重力,而BC杆计重力时,由A指向B |
A.重力对木块m做正功 |
B.木块M对木块m的支持力做负功 |
C.木块M对木块m的摩擦力做负功 |
D.木块m所受合外力对m做正功 |
A.一定等于500N | B.可能等于600N |
C.可能大于600N | D.可能小于600N |
4 |
3 |
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