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

question 21

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