Chapter 15 - Kinetics of a Particle: Impulse and Momentum - Section 15.2 - Principle of Linear Impulse and Momentum for a System of Particles - Fundamental Problems - Page 246: 4

$20m/s$

First, we calculate the impulse and then using it, we will determine the speed. $I=\frac{6000(2)}{2}+6000(6-2)=30000N.s$ Now the speed is given as $v=\frac{I}{m}$ We substitute the known values into the above equation $v=\frac{30000}{1500}=20m/s$