Suppose that the radius of the circular path is r when the speed of the rocket is v and the acceleration of the rocket has magnitude a. if the radius and speed are increased to 2r and 2v respectively, what is the magnitude of the rocket's subsequent acceleration?

a) 3 b) 2a c) a d) 4a e) 8a

Emmy kicks a soccer ball up at an angle of 45° over a level field. she watches the ball's trajectory and notices that it lands, two seconds after being kicked, about 20 m away to the north. assume that air resistance is negligible, and plot the horizontal and vertical components of the ball's velocity as a function of time. consider only the time that the ball is in the air, after being kicked but before landing. take "north" and "up" as the positive ‑ and ‑directions, respectively, and use ≈10 m/s2 for the downward acceleration due to gravity.