Two masses (5.3kg and 7.5kg) are fastened together with a small amount of explosive. They are loaded into a spring gun that is tilted 60.0 ◦ above the horizontal and launched at a speed of 25m/s. At the top of the trajectory, the explosive detonates (assume the mass of explosive is negligble). After it detonates, the 5.3kg mass isn’t moving at all. What is the velocity of the second mass just after the explosion?