In connective tissue, the role of elastic fibers is to

The role of elastic fiber is to keep the tissue length(or elasticity). That means if the tissue is stretched the elastic fiber will exert force to make it back into the normal length. This fiber can be found in skin and lack of it will make wrinkle. Other connective tissue would be collagen which will give strength

If it is still, it will tend to remain still, due to inertia. But a net force would start it moving. 
If it is moving, it will tend to continue moving, due to inertia. But a net force, in the right direction, could cause it to stop. But if that force continues, it will start moving in the opposite direction.

Hope this helps  :)