Imagine a stationary rocket in outer space. Initially, the rocket and all the fuel currently on board have a combined mass of 1000 kg. For a period of 5 s, the rocket ignites and starts to move...

Imagine a stationary rocket in outer space. Initially, the rocket and all the fuel currently on board have a combined mass of 1000 kg. For a period of 5 s, the rocket ignites and starts to move forward. It discharges spent fuel at a rate of 5 kg/s, and the vapor leaves the nozzle at a constant speed of 500 m/s. At the end of the ignition burst, how fast is the rocket moving? Ignore the effects of any gravitational fields.