(13%] Problem 8: Bob drops a ball from rest out of the window of a building. At the very same instant Phyllis launches a ball upwards with an initial speed of 11 0 my's from a point 20.0 m directly below Bob. ($33% Part (o) At what height above Phyllis in meters do the balls colicle? Grade Summary 1 = 438801 m Deductions 59% Potential (0%) Problem 9: A model rocket, initially at rest on the ground, accelerates straight upward from rest with a time varying acceleration given by aff = (1-20 m/s6, This powered launch period lasts for time : = 2.1 s until fuel is exhausted. After that, the rocket continues to move upwards but under only the influence of gravity. Ignore air resistance and take g = 9.81 myst. Co # Find the maximum height in meters reached by the rocket relative to the ground. Grade Summary Are = 10.171 Im