Answer:
4.6s
Explanation:
v=u+at
0=22.5+(-9.8)t
-22.5=-9.8t
t=-22.5/-9.8
t=2.295 s
The total time will double
2.295×2=4.59s
=4.6s
Acceleration required to stop rocket:
2as = v² - u²
a = -(18)²/(2 x 265)
a = 0.61 m/s² upwards
Resultant force = mass x acceleration
Resultant force = upwards thrust - weight
1.14 x 10⁴ x 0.61 = Thrust - 1.14 x 10⁴ x 1.6
Thrust = 2.52 x 10⁴ Newtons
