(a) What minimum thrust must the engines of a 2.0 × 10⁵ kg rocket have if the rocket is to be able to slowly rise from the Earth when aimed straight upward? 

(b) If the engines eject gas at the rate of 20 kg/s, how fast must the gaseous exhaust be moving as it leaves the engines? Neglect the small change in the mass of the rocket due to the ejected fuel.