A System Comprising Two Blocks Is Shown, One of Which

Multiple Choice

A system comprising two blocks is shown, one of which is on an inclined plane. The pulley is of negligible mass and is frictionless. The system starts from rest at position 1 and accelerates. Measurements taken when the blocks reach position 2 indicate that
(1) the kinetic energy of block A has changed by 330 J;
(2) the potential energy of block A has changed by 588 J;
(3) the kinetic energy of block B has changed by 110 J; and
(4) the potential energy of block B has changed by 98 J.
The amount of mechanical energy that has been converted to heat because of friction is

A) 12 J
B) 50 J
C) 258 J
D) 478 J
E) 710 J