(hrw8c9p40) A space vehicle is traveling at 4200 km/h

Last updated: 7/10/2022

(hrw8c9p40) A space vehicle is traveling at 4200 km/h relative to the Earth when the exhausted rocket motor is disengaged and sent backward with a speed of 72 km/h relative to the command module. The mass of the motor is four times the mass of the module. What is the speed (km/h) of the command module relative to Earth after the separation? (Note: this answer requires slightly higher precision than normal.)