A1000 kg weather rocket is launched straight up. the rocket motor provides a constant acceleration for 16 s, then the motor stops. the rocket altitude 20 s after launch is 5100 m. you can ignore any effects of air resistance. what is the rocket's speed as it passes through a cloud 5100 m above the ground? not sure what i'm doing.

22. the top of a cliff is located a distance h above the ground. at a distance h/2 there is a branch that juts out from the side of the cliff, and on this branch a bird's nest is located. two children throw stones at the nest with the same initial speed, one stone straight downward from the top of the cliff and the other stone straight upward from the ground. in the absence of air resistance, which stone hits the nest in the least amount of time?