QUESTK 



PROBLEMS. CHAPTER VIII. 173 



14. If in Fig. 114, there is also a load of 12000 Ibs. at the 

 middle, what is the maximum moment? The maximum shear? 



15. What is meant by a " fixed end " ? In which beams, 

 Figs. 94 to 113, are the shears and moments statically indeter- 

 minate? 



16. What is the maximum moment in a beam supported at 

 its ends for a load P at mid-span? What is the maximum mo- 

 ment if the ends of the beam are fixed, and where does it occur? 



17. Where does the maximum moment occur in a beam 

 having fixed ends and carrying a uniform load? 



18. What is the maximum moment for live load in the 

 floor beam of a highway bridge, the total uniform load being 

 40000 Ibs. and covering a length of 20 ft., the span length being 

 21i ft.? (Fig. 106, ^=Z 8 =9 in.). 



19. If in Fig. 107, Z 1 =Z 3 =8 ft. and J 2 =18 ft., what will 

 be the moment at the middle of the beam if the load between 

 supports is 2000 Ibs. per ft., and the load on the cantilevers is 

 1500 Ibs. per ft.? 



20. Does the case shown in Fig. 108 become a statically 

 determinate one when the points of contra-flexure are known? 



21. How does the maximum moment in Fi. 108 compare 

 with that in each span when the beam is discontinuous? 



22. Deduce the equation of three moments for a uniform 

 load of w per foot on a continuous beam of three spans, l lt 1 2 , 

 and 3. 



23. In Fig. 112, what is the value of RI when there are 

 two loads, each equal to P, symmetrically situated in the outer 

 spans? 



24. Deduce the equations accompanying Fig. 98 from 

 equation (44). 



25. A traveling crane has four wheels which run on two 

 crane girders; these in turn are supported on four wheels which 

 run on crane-runway girders. If the load on each crane wheel 

 is 40000 Ibs., and the wheel base is 10 ft., what will be the max- 

 imum moment from the wheel loads, in a crane girder having a 

 span of 48 ft.? What the maximum shear? 



Ans. 770000 ft. Ibs. and 71670 Ibs. 



26. Find, in the above example, the maximum moment 



