A.mgh+mv02/2. | B.mv02/2. |
C.mv02/2-mgh | D.mgh |
1 |
2 |
1 |
2 |
1 |
2 |
1 |
2 |
A.1:1 | B.1:
| C.1:3 | D.3:1 |
A.10
| B.10
| C.10
| D.10
|
A.力F1与F2对物体做的总功为5J |
B.力F1与F2对物体做的总功为1J |
C.物体的动能增加7J |
D.物体的机械能增加7J |
A.小球的机械能减少了2mgH/3 |
B.小球的重力势能减少了2mgH/3 |
C.小球的动能增加了2mgH/3 |
D.小球的电势能减少了mgH/3 |
A.EK2>EK1 | B.EK2=EK1 |
C.EK2≤EK1 | D.条件不足,不能确定 |
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