2)
A heavy rope, 50 ft long, weighs 0.5 lb/ft and hangs over the
edge of a building 120 ft high.
(a) How much work is done (in ft-lb) in pulling the rope to the
top of the building?
work done = ( ) ft lb
(b) How much work is done (in ft-lb) in pulling half the rope to
the top of the building?
work done= ( ) ft lb
A bucket that weighs 4 lb and a rope of negligible weight are
used to draw water from a well that is 80 ft deep. The bucket
starts with 40 lb of water and is pulled up at a rate of 2 ft/s,
but water leaks out of a hole in the bucket at a rate of 0.2 lb/s.
Find the work done (in ft-lb) in pulling the bucket to the top of
the well.
work done = ( ) ft lb