A rocket is fired vertically up from the ground with a resultant acceleration of 10 m/s2, The fuel is finished in 1 min and it continues to move up g=10 m/s2

At 60 s,h1=12×10×(60)2=18000 m v1=10×60=600 m/sAfter thath2=v122g=18000 m Hmax=h1+h2 =36000 m=36 kmFurther, -18000=600t-5t2or t2-120t-3600=0or t=120+14400+144002=120+12022=60+602∴ Total time =60+(60+602)=(120+602)s