Kepler's second law implies what about planetary motion?

His 2nd law says that the line from the sun to the planet sweeps over equal areas in equal periods of time. This implies that the planet has to move faster in its orbit when it's closer to the sun (like the Earth is in January), and slower when it's farther from the sun (like the Earth is in July).

Nps pollution is caused by rainfall or snowmelt moving over and through the ground. nonpoint source pollution can include: excess fertilizers, herbicides and insecticides from agricultural lands and residential areas. oil, grease and toxic chemicals from urban runoff and energy production

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other