题目内容：

下图均是课本中的演示实验，指出它们分别说明了什么物理现象?

(1)图(a)说明了____________________________________________________．

(2)图(b)说明了____________________________________________________．

(3)图(c)说明了____________________________________________________．

(4)图(d)说明了____________________________________________________．

(5)图(e)说明了____________________________________________________．