2nd post

A structure is a collection of elements arranged in an optium way to support a body or an object.

Mass structures: These are solid, heavy, and very stury structures. Like walls,dams, etc.

Frame structures: These structures are formed by columns and beams that act as supporting elements. One example is the structure of a building.

      Truss structures: These structures  sre composed of bars that form triangles. They are lightweight and sturdy.For example electricy pylons

Suspended structures.these are held in place by cables and suspenders attached to sturdy supports.For example bridges, tents, etc

a force is an influence thatcan deform a body or change its movement or produce motion in a body at rest.

stresses are the physical demands that a body or objet must withstand when one or more external forces applied to it.