△v |
△t |
4 |
3 |
. |
v |
vt |
2 |
. |
v |
vt |
2 |
4 |
3 |
A.6m | B.27m | C.39m | D.54m |
A. | B. | C. | D. |
A.甲、乙两物体在4s末相距最远 |
B.甲、乙两物体在5s末相遇 |
C.前4s内甲物体总在乙的前面 |
D.甲、乙两物体在2.5s末相距最远 |
A.水平拉力的大小为0.1N,方向与摩擦力方向相同 |
B.水平拉力对物体做功的数值为1.2J |
C.撤去拉力后物体还能滑行7.5m |
D.物体与水平面间的动摩擦因数为0.1 |
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