Step-by-step explanation:
It is given that,
Height, h = 3.1 m
Initial speed of the rocket, u = 0
Final speed of the rocket, v = 28 m/s
(b) Let a is the acceleration of the rocket. Using the formula as :



(a) Let t is the time taken to reach by the rocket to reach to a height of h. So,


t = 0.22 seconds
(c) At t = 0.1 seconds, height of the rocket is given by :


h = 0.63 meters
(d) Let v' is the speed of the rocket 0.10 s after launch.
So,


v' = 12.64 m/s
Hence, this is the required solution.