A Rocket with an Initial Mass of 1000 Kg Adjusts

Multiple Choice

A rocket with an initial mass of 1000 kg adjusts its thrust by varying the rate at which mass is ejected. The ejection speed relative to the rocket is 40 km/s. If the acceleration of the rocket is to have a magnitude of 20 m/s² at an instant when its mass is 80% of the original mass, at what rate is mass being ejected at that instant? Ignore any external forces on the rocket.

A) 0.40 kg/s
B) 0.50 kg/s
C) 0.60 kg/s
D) 0.70 kg/s
E) 0.80 kg/s