(a) Resultant vertical acceleration, a=10ms−2 Height travelled by the rocket in 1 min (60s), h=ut+
1
2
at2 =0×60+
1
2
×10×(60)2 =18000m=18km Velocity of rocket after 1 min (60s), v=u+at=0+10×60=600ms−1 After 1 min, when fuel of rocket is finished, then u=600ms−1,a=−g=−9.8m∕s2 Hence, if rocket goes at height h2, then v2−u2=2gh2 0−(600)2=2(−9.8)h2 h2=
360000
2×9.8
=18367.3m=18.4km ∴ Maximum height travelled by rocket from ground =h1+h2=18+18.4=36.4km
