Problem 2: Firecracker explosion (5 pts.) Initial Final A pyrotechnician releases a 3 kg firecracker from rest. 1 = 0.4 s 1 0.8 s At t = 0.4 s the firecracker is moving downward with speed 4 , when it begins to explode into two pieces 10 1= 4m/s with masses mtop = 1 kg and mbottom = 2 kg. At the m = 3 kg end of the explosion (t = 0.8 s), the top piece is moving MIOD = 1 kg upward with speed 4 . A. What is the magnitude and direction of the total 101= 4m/s moontom = 2 kg impulse exerted on the entire firecracker during the explosion? U bottom = ? B. What is the speed of the bottom portion of the firecracker