11.45 Two rockets are launched at a fireworks display. Rocket A is launched with an initial velocity vo 100 m/s and rocket B is launched I seconds later with the same initial velocity. The two rockets are timed to explode simultaneously at a height of 300 m as A is falling and B is rising. Assuming a constant acceleration g = 9.81 m/s, determine (a) the time t₁, (b) the velocity of B relative to A at the time of the explosion. 11.