Usually folks figure sand at 100 pcf. There are 27 cubic feet in a cubic yard. So to continue the answer the previous poster made... Using the 100 pcf average weight for sand, and that there are 27 cubic feet in a yard, then 2 yards is equal to 54 cubic feet and at 100 pcf, the total weight is 5400 lbs, or 2.7 tons.
The walking distance measure denotes the distance that can be travelled by walking in a fixed amount of time. In Japan, the standard measure for walking distance is 80 meters for 1 minute of walking time. It is the standard used in real estate listings. For example, if a building is a 10 minute walk from a particular park or train station, it is 800 meters away.
If you are not already walking long distances when you work out, then you are going to need to start at square one to build up your endurance. Typically, the average person may walk just a couple of miles everyday to get exercise. It can take up to 30 minutes for you to walk this distance. Building up endurance takes more time, though. Ideally, you want to start off an endurance walking workout by stretching your legs and arms thoroughly before you start.