At the start of the flight, when the velocity of the rocket is zero, the ejected exhaust is moving to the left, relative to our coordinate system, at 2400 m/s. at the end of the first second, the rocket is moving at 40 m/s. the speed of the exhaust relative to our system is 2360 m/s. we could now compute the acceleration at t=1.0 s (using the decreased rocket mass), find the velocity at t=2.0 s, and so on, stepping through the calculation one second at a time until all the fuel is used up. as the mass decreases, the acceleration in successive 1 s intervals increases. a. find the rocket velocity after 2 seconds of launchb. find the rocket veloctiy after 3 seconds of launch.