13. A bomb initially at rest on a smooth, horizontal surface is exploded into three pieces. Two pieces fly off horizontally at a 60° angle to each other, a 2.0 kg piece at 20 m/s and a 3.0 kg pieceat 12 m/s. The third piece flies off horizontally at 30 m/s. a. Determine the direction of motion of the third piece. b. What is its mass?

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