A. A force that acts on a body moving in a circular path
An element is a pure substance made up of only one kind of atom. An element is composed of atoms in which it is composed of neutrons and protons. The nucleus is surrounded by electrons. The answer to this problem is A. element
Answer: The force on the firefly
The unfortunate firefly hitting the bus does not change the velocity of the bus very much. Technically there is a change, but it's so very small and miniscule that it barely registers. To any casual observer not paying very close attention, they don't notice anything at all. So effectively the force on the firefly is a lot greater since the firefly got the worst end of the deal.
So in short, we look at the velocity of each object and see which velocity changed the most. In this case, the firefly's velocity changed from whatever speed it was flying to 0 when it stops flying all together. That's why the force is greater on the bug.
Answer: 3 times as much the potential energy
Explanation:
Potential energy is the energy possessed by an object by virtue of its position.

m= mass of object
g = acceleration due to gravity
h = height of an object
When same object with same is lifted from 10 feet to 30 feet. The height has increased 3 times , thus the potential energy will also get 3 times as much.