Answer
(a) $PE = 35.6~J$
(b) $PE = 9.70~J$
(c) The work done by the person to lift the book from the ground to 2.20 meters high is 35.6 J. The work done by the person to lift the book from a height that is level with the top of the head to 2.20 meters high is 9.70 J.
Work Step by Step
(a) $PE = mgy = (1.65 ~kg)(9.80 ~m/s^2)(2.20 ~m)$
$PE = 35.6~J$
(b) $PE = mgy = (1.65 ~kg)(9.80 ~m/s^2)(0.60 ~m)$
$PE = 9.70~J$
(c) The work done by the person to lift the book from the ground to 2.20 meters high is 35.6 J. The work done by the person to lift the book from a height that is level with the top of the head to 2.20 meters high is 9.70 J.
