I I am really really confused about these two questions does anybody know the answer to both of them

1) Topographic maps show contours, elevation, forest cover, marsh, pipelines, power transmission lines, buildings and various types of boundary lines such as international, provincial and administrative, and many others. ( Elevation)

2) Contour line, a line on a map representing an imaginary line on the land surface, all points of which are at the same elevation above a datum plane, usually mean sea level. The diagram illustrates how contour lines show relief by joining points of equal elevation. ( Contour Line)

explanation:

the universal gravitation equation. since the gravitational force is directly proportional to the mass of both interacting objects, more massive objects will attract each other with a greater gravitational force. if the mass of one of the objects is doubled, then the force of gravity between them is doubled.