如图所示,质量mA="2" kg木块A静止在光滑水平面上。一质量mB=" 1"

题型:计算题

问题:

如图所示,质量mA="2" kg木块A静止在光滑水平面上。一质量mB=" 1" kg的木块B以某一初速度v0="5" m/s向右运动,与A碰撞后均向右运动。木块A 向右运动,与挡板碰撞反弹(与挡板碰撞无机械能损失)。后来与B发生二次碰撞,碰后A、B同向运动,速度分别为0.9 m/s、1.2 m/s。求:

(1)第一次A、B碰撞后A的速度;

(2)第二次碰撞过程中,A对B做的功。

考点:动量定理
题型:计算题
30
7
×(
7
15
-
3
20
)-
5
14
=
13
3
4
×
5
8
-2
3
4
×
5
8
-
5
8
=
(8
5
12
+3
4
7
)-(
4
7
-
7
12
)
=
2.5×
3
7
×0.4×2
1
3
=
题型:计算题

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题型:计算题

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A.曲面造型

B.实体造型

C.参数化造型

D.变量化造型

题型:计算题

根据孟代尔-弗莱明模型的假定,图形分析中的BP曲线是()

A.向右下方倾斜

B.是一条垂线

C.向右上方倾斜

D.是一条水平线

题型:计算题

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