a construction crew wants to extend a uniform rigid metal bar of length 7m and mass 400kg between two platforms which lie on the same horizonantally level. the platforms are separated by the distance of 5m.
a. what is the minimum downward force that must be applied to the bean to ensure that it can be extended horizonantlly over the distance separating the two platforms?
b. What force does the beam exert on the edge of the platform?