It depends on what direction it moves the dirt.
If it moves the dirt horizontally, then the answer depends on several more
quantities that we don't know about.
If it moves the dirt vertically, then the machine does
(1100 lb x 1 ft) = 1,100 ft-lbs of work per second.
1 horsepower = 550 ft-lbs per second.
So the machine does work at the rate of
(1100 ft-lbs / second) / (550 ft-lbs / second)
= 2 horsepower .
