Answer:
a. he uses sharp contrast in light
Explanation:
In archaeology, rock art is human-made markings placed on natural stone; it is largely synonymous with parietal art. A global phenomenon, rock art is found in many culturally diverse regions of the world. It has been produced in many contexts throughout human history, although the majority of rock art that has been ethnographically recorded has been produced as a part of ritual. Such artworks are often divided into three forms: petroglyphs, which are carved into the rock surface, pictographs, which are painted onto the surface, and earth figures, formed on the ground. The oldest known rock art dates from the Upper Palaeolithic period, having been found in Europe, Australia, Asia and Africa. Archaeologists studying these artworks believe that they likely had magico-religious significance.
Think of Einstein’s theory of general relativity. If a wide receiver making a catch collides in midair with the defender, the defenders often fair little better in these situations because they tend to run a little larger than receivers. But it is not a matter of force. Newton’s third law of motion (“to every action there is an equal and opposite reaction / the mutual actions of two bodies upon eachother are always equal and directed to contrary parts”) implies that this issue has to do with momentum, the product of mass and velocity. A force between two objects is an interaction that changes momentum. If the momentum of one increases, the momentum of the other will decrease by a substantial amount. All that is needed to be thought about is is the momentum right before the two come into contact and the momentum right after they stop interacting.
