A model rocket rises with constant acceleration to a height of 4.0 m, at which point its speed is 25.0 m/s. How long does it take for the rocket to reach this height? Ans: t= 0.32s What was the magnitude of the rockets acceleration? Ans a= 78 m/s^2 "Find the height of the rocket 0.20 seconds after launch." I cant seem to get it right, I know its at least close to 1.5, because that was my original answer but the darned online system says "Not quite. Check through your calculations; you may have made a rounding error or used the wrong number of significant figures." the answer is supposed to be to two significant figures. "Find the speed of the rocket 0.20 seconds after launch." I havent attempted this part of the question yet because I think I need to use what I figure out from the previous question to work on this. All this stuff is not hard, but I cant seem to grasp the simple concepts that Im missing in figuring it out, any help and/or guidance would be really appreciated.