B. The student should model a convex lens because it directs light toward the center of the lens.
Explanation:
Lenses are optical devices that work on the principle of refraction.
Refraction is a phenomenon of wave (such as light waves) that occurs when a ray of light crosses the interface between two mediums with different optical density: when this occurs, the ray of light bends and change speed.
In particular, there are two types of lenses:
Convex lenses: these lenses are curved outward at their center, therefore the rays of light coming from infinite distance (parallel to the axis) are all focused into a point of the lens, called principal focus. Therefore, a convex lens directs lights towards this point.
Concave lenses: these lenses are curved inward at their center, therefore the rays of light coming from infinite distance are bent away from the principal focus. Therefore, this is a diverging lens, as the rays of light do not converge.
So, the correct answer is
B. The student should model a convex lens because it directs light toward the center of the lens.
Natural sources include decomposition, ocean release and respiration. Human sources come from activities like cement production, deforestation as well as the burning of fossil fuels like coal, oil and natural gas.
