Two buckets of nails are arranged in a pulley system as shown in the figure; the pulley itself is both massless and frictionless and the rope may be...

D

M

m

As the heavier bucket moves downward to the ground, what will have been the change in mechanical energy of the lighter bucket, and what will have been the tension in the rope?

Give your answer as an ordered pair, with the change in mechanical energy first, followed by a comma, followed by the tension in the rope.