The elevation of the end of a steel beam supported by a concrete floor is adjusted by

Question:

The elevation of the end of a steel beam supported by a concrete floor is adjusted by means of the steel wedges E and F. The base plate CD has been welded to the lower flange of the beam, and the end reaction of the beam is known to be 90 KN. The coefficient of static friction is 0.30 between the two steel surfaces and 0.60 between the steel and the concrete. If the horizontal motion of the beam is prevented by the force
Q, determine
(a) The force P required for impending upward motion of the beam,
(b) The corresponding force Q.