A store sells a variety of sets for building molecular models. The sets are described by the diagram below. Each circled letter represents a box of 6 model atoms of one element. For example, the circled letter "P" represents a box with 6 model phosphorous atoms.

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on

Where is the data? ? and graph