Detailed solution is as follows,
Tractor Productivity
For the given seismic wave velocity,ie., 5,000 fps and using 370
hp tractor ,referring the tractor production chart,
Productivity =560 bcy/hr
Quantity of rock
Given Length =15000 ft
Width = 85 ft
depth =3 ft
Volume of rock = 15000 x 85 x 3
                     Â
=3825000 cft
Total duration required to cut
Per day productivity =productivity per hour x no of hours worked
in a day
                           Â
=560 x 10
                           Â
=5600 cft
No of days required to complete the work = total
volume/productivity per day
                                                          Â
=3825000/5600Â Â Â Â Â Â Â
                                                          Â
=683 days
