Evan is building a toy rocket. He wants to fill the rocket with high-pressure water in order to launch it into the air. Which of the following materials would be the best choice for constructing the outside of the rocket? A. small paper garbage bag
B. a two-liter plastic bottle
C. a cardboard box
D. a small plastic garbage bag

At a certain instant after jumping from the airplane a, a skydiver b is in the position shown and has reached a terminal (constant) speed vb = 52 m/s. the airplane has the same constant speed va = 52 m/s, and after a period of level flight is just beginning to follow the circular path shown of radius ρa = 2330 m. (a) determine the velocity and acceleration of the airplane relative to the skydiver. (b) determine the time rate of change of the speed vr of the airplane and the radius of curvature ρr of its path, both as observed by the nonrotating skydiver.