Hello, 1. The problem statement, all variables and given/known data I'd like to find P=F dot v that a monkey of mass m must exert upon climbing up a closed loop of rope of mass M, wrapped around a massless pulley, so that it (viz. the monkey) at any given moment remains in the same place. The rope is constantly tight and at t=0 the rope and the monkey are at rest. No friction is involved! And the monkey has no volume. 2. Relevant equations 3. The attempt at a solution I am not sure whether "monkey stays in the same place" entails dy/dt=0 for the monkey or, rather, that its acceleration is basically that of the rope but in the opposite direction. Further, I wrote the following equation for the forces which "feels" the rope: -(M+m)g(y^) + F(y^) = My'' where F is the force with which the monkey pulls the rope. I am also not sure whether this is correct. I'd appreciate some insight on all of the above.