This is a great assignment that captures exactly what was asked from you. You’ve decided to move in closer and change your framing to place more emphasis on the motion of the water rather than the overall makeup of the object.
By moving in closer you’ve also managed to simplify your background and help isolate your main area of interest. Your first image lacked a “stopper” while your second image incorporated the falling water as your primary object (i.e. stopper) while still using the textures of the rocks and metal as your secondary objects.
Your first image lacked a sense of depth. The main object is only inches away from the background and you have no foreground element. In your second image however, you have exaggerated the sense of depth by using a shallower depth of field and using part of the object as a strong foreground object. Incorporating depth and 3 dimensionality into your work will be important to future projects. What you’ll need to focus on now is incorporating the things you’ve done in macro, to braver photographs that include more of the background.
The other thing I think you’ll really enjoy experimenting with is lighting. Play around with your house lamps, flashlights, soft lighting, hard lighting and directional lighting. It will completely transform your images.
Please watch the following two videos on lighting:
Lighting Tutorial
http://www.youtube.com/watch?v=A6JFVHRwJwc&feature=channel_page
Lighting Color temperature:
http://www.youtube.com/watch?v=mwqNRqDx680&feature=channel