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一、选择题：

1、图中的实线表示t时刻的一列简谐横波的图像,虚线则表示(t+△t)时刻该波的图像.设T为该波的周期.则△t的取值( ).(其中n＝0,1,2,3…)

(A)若波沿x轴正方向传播,△t＝(n+)T

(B)若波沿x轴负方向传播,△t＝(n+)T

(C)若波沿x轴正方向传播,△t＝(n+)T

(D)若波沿x轴负方向传播,△t＝(n+1)T

2、声音从声源发出,在空气中传播时( ).

(A)传播距离越远声波速度越小

(B)传播距离越远声音频率越低

(C)传播距离越远声波的振幅波越小

(D)传播距离越远声波的波长越短

3、将摆球质量一定、摆长为l的单摆竖直悬挂中升降机内,在升降机以恒定的加速度a(a

(A) 2π(B) 2π

(C) 2π(D) 2π

4、对单摆在竖直面内的振动,下面说法中正确的是( ).

(A)摆球所受向心力处处相同

(B)摆球的回复力是它所受的合力

(C)摆球经过平衡位置时所受回复力为零

(D)摆球经过平衡位置时所受合外力为零

5、一轻弹簧上端固定,下端挂一重物,平衡时弹簧伸长了5cm.再将重物向下拉1cm,然后放手,则在刚释放的瞬间重物的加速度是(g取10m∕s2)( ).

(A)2.0m∕s2(B)7.5 m∕s2

(C)10 m∕s2(D)12.5 m∕s2

6、在某行星表面处的重力加速度值是地球表面处重力加速度值的4∕9,那么把在地球表面上走得很准的摆钟搬到这个行星表面上,它的分针转一圈经历的时间实际应是( ).

(A)2.25h(B)1.5h(C)4∕9h(D)2∕3h

7、一个单摆,分别在Ⅰ、Ⅱ两个行星上做简谐振动的周期为T1和T2,若这两个行星的质量之比为M1：M2＝4：1,半径之比为R1：R2＝2：1,则( ).

(A)T

：T2＝1：1 (B)T1：T2＝2：1

1

(C)T

：T2＝4：1 (D)T1：T2＝2：1

1

8、图是一水平弹簧振子做简谐振动的振动的振动图像(x-t图),由图可推断,振动系统( ).

(A)在t

和t2时刻具有相等的动能和相同的动量

1

(B)在t

和t4时刻具有相等的势能和相同的动量

3

(C)在t

和t6时刻具有相同的位移和速度

4

(D)在t

和t6时刻具有相同的速度和加速度

1

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