Amodel rocket blasts off and moves upward with an acceleration of 12 m/ss until it reaches a height of 29 m, at which point its engine shuts off and it continues its flight in free fall.

upward acceleration of rocket is given as

now the speed of rocket is given as

Here we can use kinematics again as after this the rocket starts free fall so its acceleration is a = 9.8 m/s^2

so the maximum height achieved by the rocket will be

now the time of flight of rocket will be given as

first it will reach to height h = 29 m

now after this it will move under free fall so time to reach the ground is given by

by solving above equation

So total time of motion is

a electromagnetic waves