1. The problem statement, all variables and given/known data The first stage of a Saturn V space vehicle consumes fuel at the rate of 47400 kg/s, with an exhaust speed of 2820 m/s. The acceleration of gravity is 9.8 m/s2 . Calculate the thrust produced by these en- gines. Answer in units of N. (part 2 of 2) 10.0 points Note: You must include the force of gravity. Find the initial acceleration of the vehicle on the launch pad if its initial mass is 1.1 × 107 kg. Answer in units of m/s2. 2. Relevant equations vrel*r= ma = thrust 3. The attempt at a solution For the first part, I got 133668000 N, which is right. For the second part I divided the answer to the first part by the given mass. I got 12.51 m/s^2. Then to account for the acceleration of gravity, I subtracted 9.81 m/s^2 and got 2.3 m/s^2. However, that's not the correct answer. What am I doing wrong here? Can I not substract accelerations like that? It seems to me, I should be able to-- They're vector quantities acting in opposite directions.