So the problem is: a 1000 kg rocket is fired straight up, a 100 kg rocket is fired straight up with a constant acceleration for 16 seconds. It then stops accelerating and 20 seconds after launch reaches a height of 5100 m. Ignore air resistance. Find the acceleration of the rocket for the first 16 seconds and the velocity of the rocket at 5100 m. So in my physics class the only equations we have learned are the kinematics of constant acceleration in 1 dimension equations, and that is what the chapter this problem is from is based on. I first tried using y = y_initial + (v_initial * t) + (1/2 * g * t^2) , but there are to many unknown values to make any use of it. The values I were able to figure out from the problem are: First 16 seconds x = ? x_initial = ? v = ? v_initial = ? g = ? t = 16 Free Fall x = 5100 x_initial = ? v = ? v_initial = ? g = -9.8 t = 4 basically I don't know where to go from here, and am just looking for some direction. Also I am unsure whether the 1000 kg plays any part in the problem, since we have not done anything with weight in our class, but if it does, feel free to provide me with some enlightenment. Thanks for any help and if any extra info is needed let me know.