A model rocket blasts off from the ground, rising straight upward with a constant acceleration that has a magnitude of 76.7 m/s2 for 1.89 seconds, at which point its fuel abruptly runs out. Air resistance has no effect on its flight. What maximum altitude (above the ground) will the rocket reach?

Answer 1

V1 = a*t = = 76.7 * 1.89 = 145 m/s.
h1 = 0.5a*t^2 = 0.5*76.7*1.89^2 = 137 m.

h2 = h1 + -V1^2/2g=137 + (-145)^2/-19.6 =
1210 m. Above gnd.