This is a very good assignment.
Let’s start by looking at the photograph of the waterfall. For starters your exposure is excellent. Because of the bright tone of falling water, and your need to keep the shutter open for a longer period of time to capture the movement, it would have been really easy to overexpose the whites in this image. However, you’ve managed to keep the detail in the water without allowing your whites to become burnt out (i.e. overexposed). It seems as through your camera can handle dynamic range quite well.
You’ve also gone above and beyond what the assignment asked you to do. The composition of the shot is fantastic. You have not only a beautiful background, but you’ve also incorporated a small foreground with dramatic color highlights. In the same vein, you’ve also limited your color palette which has helped you simplify your image which has given the photograph an organized look.
Your second image is also very strong. My main concern with your second image, is that the foreground may have a little too much light on it, and the light that is on it is too flat. There seems to be a lot of texture in this object that subtle side lighting could have helped expose.
Other than that, great work!