A 2.0-kg object moving with a velocity of 5.0 m/s in the positive x direction strikes and sticks to a 3.0-kg object moving with a speed of 2.0 m/s in the same direction. How much kinetic energy is lost in this collision?
1) 2.4 J
2) 9.6 J
3) 5.4 J
4) 0.6 J
5) 6.0 J
Answer: 3