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问题 计算题

 如图18所示，在xOy平面内某介质中有一列波源位于O点沿x 轴正方向传播的简谐横波，在t=0时，P点（x=20cm处）位于波峰，t=1s时，P点位于平衡位置，且速度方向向下，Q点（x=80cm处）位于平衡位置下方的最大位移处。已知此波的振幅，波长，周期求：

（1）画出时，PQ之间的波形图（把图画在答题卷的相应位置）

（2）该波在介质中的波速

（3）在图19中画出波源O点的振动图像（把图画在答题卷的相应位置）

    

答案

（1）如图所示

（2）

（3）如图所示

（1）如图所示

（2），，

因此。

（3）如图所示

本题考查机械波的传播，根据一个周期内波传播一个波长，质点完成一个全振动求解

判断题

临时存款账户的有效期最长不得超过3年。( )
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问答题

Guanghua Company (Guanghua) and Dongda Company (Dongda) entered into a cooperation agreement to build a building jointly. They agreed that Guanghua would provide all the funds for the construction and hold half of the building, while Dongda would provide the land-use right for construction and also hold half of the building after construction; the ownership of the building would be held jointly by the two parties, but would be registered under the name of Dongda. They also stated in the agreement that any disposal of the building must only be decided with the written consent of both parties.Having completed the construction of the building and the registration of real estate, the two companies divided and held their parts of the building in light of the agreement. Several months later, in order to expand its business Dongda mortgaged the whole building to an Investment Co for RMB 10 million yuan. The mortgage agreement, registered by the parties, stipulated that if Dongda failed to pay off the principal and interest, the building would be automatically transferred to Investment Co. In doing so Dongda did not notify this transaction to Guanghua.Due to its unsuccessful new business, Dongda was unable to repay the principal and interest, Investment Co requested the transfer of the ownership of the building in light of the mortgage agreement but was refused by Dongda. Investment Co filed a lawsuit requesting the court to support this transfer. Having heard this information Guanghua also took a legal action based on the cooperation agreement, requesting the court to confirm its ownership to the building.Required:Answer the following questions in accordance with the relevant provisions of the Property Law of China and give your reasons for your answers:

(a) State whether Investment Co was a lawful mortgagee to the building. (3 marks)
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