66.] RECTILINEAR MOTION. 37 



(8) In what time would an engine yielding 2 H.P. perform the work 

 of raising the brickwork in Art. 62, Ex. (4) ? 



(9) A shaft of 8 ft. diameter is to be sunk to a depth of 420 ft. 

 through a material whose specific gravity is 2-2. Determine: (a) the 

 total work of raising the material to the surface ; (<) the time in which 

 it can be done by an engine yielding 3-5 H.P. ; (c) the time in which 

 it can be done by 4 men working in a capstan, if each laborer does 

 2500 ft.-lbs. per minute, working 8 hours per day. 



