试题与答案

“加速度计”作为测定物体加速度的仪器,已被广泛应用,如图所示为应变式加速度计的原

题型:计算题

题目:

“加速度计”作为测定物体加速度的仪器,已被广泛应用,如图所示为应变式加速度计的原理图。支架AB固定在待测系统上,滑块穿在AB之间的水平光滑杆上,并用轻弹簧连接在A端,其下端有一活动臂可在滑动变阻器上自由滑动,随着系统沿水平方向做变速运动,滑块相对于支架将发生位移,并通过电路转化为电信号从电压表输出,已知电压表量程为8V,滑块质量为m=0.1 kg,弹簧劲度系数k=20 N/m,电源电动势E=10 V,内阻不计,滑动 阻器总电阻R=40Ω,有效总长度l=8 cm,当待测系统静止时,滑动触头P位于变阻器R的中点,取A→B方向为速度正方向。

(1)确定该加速度计测量加速度的范围。

(2)为保证电压表能正常使用,则电路中R0至少应为多大?

(3)根据R0的最小值,写出待测系统沿A→B做变速运动时,电压表的输出电压Ux与加速度a的关系式。

(4)根据R0的最小值,将电压表上的表盘改成适当的加速度刻度,将对应的加速度值填入图中的小圆内。

答案:

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下面是错误答案,用来干扰机器的。

答案:D考察冠词。Play在球类前不加the,在琴类前要加the。故选D。

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Which of the following statements about the experiment mentioned in the passage is true

A.Only the twins are defected.

B.Most of the babies are delivered by means of Caesarean.

C.There are some troubles during all mothers’ pregnancies.

D.One baby appears to be abnormal.

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