posted by arcos15 .
A 19 N thrust is exerted on a 0.4 kg rocket for a time interval of 8 s as it moves straight up. (Neglect all forces except this thrust and the force of gravity.) The rocket then continues to move upward as its speed reduces steadily to zero.
(a) What is the maximum height that the rocket attains?
a. F = ma.
a = F/m = 16/0.4 = 40 m/s^2.
Vo = a*t=40m/s^2 * 8s=320 m/s.=Initial velocity.
hmax=(0-102400)/-19.6 = 5224 m.