Answer:
If an object has a high density then the molicules making up that object are closly packed togeather. Because of this, objects with a higher density will have more mass than objects of the same size that have a lesser density.
The simplest pure substances that cannot be broken down into any other substances are elements, such as gold (Au) or oxygen (O).
I'm pretty sure it's D. The stars don't influence the moon's phases.
Input work = 9.63×10³ J.
Output work = 3.0×10³ J
By definition,
Efficiency = (Output work)/(Input work)
= (3.0×10³)/(9.63×10³)
= 0.31 = 31%
Answer: 31%