The goal of Unit 11 of The Physics Classroom Tutorial is to develop an understanding of the nature, properties, behavior, and mathematics of sound and to apply this understanding to the analysis of music and musical instruments.
It's as big as the continental United States, but covered in sand. If you like to dig your feet in the sand, then the Sahara Desert is the place for you. Watch out though - it's hot! Temperatures range from 122 F to below freezing in the winter. Sand dunes can reach over 189 meters tall or be flat for miles and miles.
There are more than 500 plant species in the Sahara desert. Most of these plant species would be near the Nile. There are certain parts such as the Nile valley that are quite luscious and green but other than that, the Sahara is very barren and plain.