问题 单项选择题

A female client is discharged from the hospital after having an episode of heart failure. She’s prescribed daily oral doses of digoxin (Lanoxin) and furosemide (Lasix). Two days later, she tells her community health nurse that she feels weak and frequently feels her heart "flutter. " What action should the nurse take

A. Tell the client to rest more often.
B. Tell the client to stop taking the digoxin, and call the physiciarn.
C. Call the physician, report the symptoms, and request to draw a blood sample to determine the client’s potassium level.
D. Tell the client to avoid foods that contain caffein

答案

参考答案:C

解析:Furosemide is a potassium-wasting diuretic. A low potassium level may cause weakness and palpitations. Telling the client to rest more often won’t help the client if she’s hypokalemic. Digoxin isn’t causing the client’s symptoms, so she doesn’t need to stop taking it. The client should probably avoid caffeine, but this wouldn’t resolve potassium depletion.

单项选择题
实验题

(8分)两位同学用如图所示装置,通过半径相同的A、B两球的碰撞来验证动量守恒定律。

(1)实验中必须满足的条件是        

A.斜槽轨道尽量光滑以减小误差

B.斜槽轨道末端的切线必须水平

C.入射球A每次必须从轨道的同一位置由静止滚下

D.两球的质量必须相等

(2)测量所得入射球A的质量为mA,被碰撞小球B的质量为mB,图中O点是小球抛出点在水平地面上的垂直投影,实验时,先让入射球A从斜轨上的起始位置由静止释放,找到其平均落点的位置P,测得平抛射程为OP;再将入射球A从斜轨上起始位置由静止释放,与小球B相撞,分别找到球A和球B相撞后的平均落点M、N,测得平抛射程分别为OM和ON。当所测物理量满足表达式                 时,即说明两球碰撞中动量守恒;如果满足表达式               时,则说明两球的碰撞为完全弹性碰撞。

(3)乙同学也用上述两球进行实验,但将实验装置进行了改装:如图所示,将白纸、复写纸固定在竖直放置的木条上,用来记录实验中球A、球B与木条的撞击点。实验时,首先将木条竖直立在轨道末端右侧并与轨道接触,让入射球A从斜轨上起始位置由静止释放,撞击点为B′;然后将木条平移到图中所示位置,入射球A从斜轨上起始位置由静止释放,确定其撞击点P′;再将入射球A从斜轨上起始位置由静止释放,与球B相撞,确定球A和球B相撞后的撞击点分别为M′和N′。测得B′与N′、P′、M′各点的高度差分别为h1、h2、h3。若所测物理量满足表达式                 时,则说明球A和球B碰撞中动量守恒。