• as it sits on top of a building that is 50 meters tall. • as it is half-way through a fall off a building that is 50 meters tall and travelling 19.8 meters per second.
• as it is just about to hit the ground from a fall off a building that is 50 meters tall and travelling 28 m/s
What is the potential energy of the ball as it is half-way through the fall (25 meters high)?

Does anyone know a lot about how to: - calculate mass of magnesium metal - calculate the actual yield of magnesium oxide - calculate the theoretical yield of mgo - calculate the percent yield of mgo - determine the percent yield of mgo - determine the average percent yield of mgo i had to do an online lab and its asking these questions but i have no idea where to start or how to be able to find these things. i can post the chart of the data from the lab or if you can tell me exactly how i can find each.

Which statements describe polyatomic ions? check all that apply. polyatomic ions have many charges. polyatomic ions have one overall charge. polyatomic ions repel other ions to form ionic bonds. polyatomic ions attract other ions to form ionic bonds. polyatomic ions are made up of only one type of atom. polyatomic ions are made up of two or more types of atoms.

How manyatoms of mercury are in 1.4214e+1 ml sample