You are trying to find the optimal speed for making the turn without the force of friction. Therefore, this force does not need to be considered in your calculations. You are dealing with the force of gravity and the normal force only. There is centripetal force, of course, but this is...
The question you were confused on can be rewritten as 2(3+2a) + 2a, which is the same format as your other problems. See how this is different than what you originally solved, which was (2+2a)(3+2a)?
Homework Statement
A 975-kg two-stage rocket is traveling at a speed of 5.80 x 103 m/s with respect to Earth when a predesigned explosion separates the rocket into two sections of equal mass that then move with a relative speed (relative to each other) of 2.20 x 103 m/s along the original line...
You have to be sure that you separate your x and y components. If the rock is being thrown horizontally, v0x = 23.0 m/s and v0y = 0 m/s. See what I mean? You will have to use trig to find the final velocity (usually the inverse tangent of vy and vx).
Some other useful functions (I've written...