Question

For a Rocket propulsion velocity of exhaust gases relative to rocket is 2km/s. If mass of rocket system is 1000 kg, then the rate of fuel consumption for a rockt to rise up with acceleration `4.9 m//s^(2)` will be:-
A. 12.25 kg/s
B. 17.5 kg/s
C. 7.35 kg/s
D. 5.2 kg/s

Answer 1

Correct Answer - C
`Here" "v(dm)/dt=m(4.9+9.8)=(14.7)m`
`v=2km//s" "m=1000`
`2000(dm)/(dt)=14.7xx1000`
`(dm)/(dt)=14.7/2=7.35 kg//s`