A Block of Mass M = 9 $0.50 \mathrm {~m} / \mathrm { s }$

Multiple Choice

A block of mass m = 9.0 kg and speed V and is behind a block of mass M = 27 kg and speed of $0.50 \mathrm {~m} / \mathrm { s }$ as shown int the figure.The surface is frictionless,and the blocks suddenly collide and couple.After the collision,the blocks have a common speed of 0.90 m/s.How much kinetic energy of the blocks is lost due to the collision?

A) 8.6 J
B) 2.0 J
C) 4.6 J
D) 11 J
E) 31 J