A rocket set for vertical firing with a resultant acceleration of 5m/s2. If the fuel is finished in 2  minutes, then the maximum height reached by the rocket  is g=10m/s−2

The height attained by rocket in 2 minutes is  by the question, initial velocity=U=0;acceleration = a=5 m/s2;time elapsed=t=2×60=120sec;displacement=S=h1  S=Ut+12at2 ⇒h1=125×120×120 ⇒h1=36km---(1)Velocity gained by the rocket from  V=U+at,V=0+5×120=600m/s The height attained after 2 minutes is  h2=V22g⇒h2=60022×10=18000m⇒h2=18kmTotal height attained by rocket H=h1+h2=36+18=54km