For an observer who stays in one spot when the source of a sound is moving,

the sound wave's:

O

A. frequency changes.

O

B. amplitude decreases.

O

C. speed increases.

O

D. amplitude increases.

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.

Why does a red shoe appear red in daylight

Asolution is made by dissolving 25.5 grams of glucose (c6h12o6) in 398 grams of water. what is the freezing point depression of the solvent if the freezing point constant is -1.86 °c/m? show all of the work needed to solve this problem.