1. The problem statement, all variables and given/known data First, this is not an assignment, per se, it is for my own help, and If someone could help me work it through that would be much appreciated. An object of mass 1 Kg is launched at an angle of 42° from the horizontal at 180 m/s. A force of drag acts on it that is dependant on its velocity, with the force being equal to -.012V. What energy does the ball have when it reaches its maximum height? 2. Relevant equations I solved the initial components in both the x and y directions and got 133.8 m/s and 120 m/s. Other equations: E=K+U K=.5mv^2 U=mgh x(t)=x+(integral)v(t)dt I am sure I am missing some, which is part of my problem. 3. The attempt at a solution I started with F=mdv/dt Integrated to Integral from Vi to V (dv')/fv'=t/m which didnt help much. I then tried mdv/dt=mg-kv (kv being my -.012v) But, was having trouble with my signs, and it didnt look like it was coming out right. THe retarding forces in the y direction are -mg-.012v and the x direction is only -.012 v Going to F=ma I tried various substitutions and again, had little luck. I know I wiill need to solve the height at which the velociy is zero, using only the y component to get potential enrgy, and also find the x velcity at this time to get the kinetic energy and then add them up to get the total energy. The thing that is giving me difficult is the retarding force as a function of the velocity, so the force will be constantly changing. If anyone could help that would be very much appreciated!