Alex's rocket lands after 4.56s and Billy's lands after 5.21s. What was the initial (maximum) vertical velocity of both of their rockets as they left the launchpad to 3s.f.?

Application of suvat equation v=u+at. Students acknowledge that at the rocket's maximum height it will have a velocity of 0. They also realise that the time to reach thi s point from launch is half the total flight time of each rocket.v=u+at v=0, u=?, a=-9.81, t= T/2u=v-atu_a=9.81 x 4.56/2 AND u_b=9.81 x 5.21/2u_a= 22.4m/s u_b= 25.5m/s