18. Electromagnetic energy can exert a force on surfaces that it strikes (this phenomenon is called radiation pressure).

(a) Will this force be greater on a shiny or a dark surface?

(b) For the same surface, would you expect the force on it to be greater using a bright source rather than a fainter source of the same color? Explain.

(c) For a given surface, would you expect the force on it to vary with distance from a light source? For all parts, clearly explain your reasoning.