http://img412.imageshack.us/img412/7050/blockspringrampfrictionfy0.gif [Broken] A man pulls a block of mass m = 20 kg up an incline at a slow constant velocity for a distance of d = 3.5 m. The incline makes an angle q = 33° with the horizontal. The coefficient of kinetic friction between the block and the inclined plane is µk = 0.2. a) What is the work Wm done by the man? b) What is the speed v of the block when it first reaches the horizontal surface? c) What is the spring constant k of the spring? d) How far up the incline d1 does the block rebound? Relevant equations: Wtotal = Change in Kinetic energy Ffriction = Coefficient of friction(Fnormal) Fspring = kx (1/2)mv^2 I know there are the force of friction, the man, and gravity on the box. I started by saying: Wman - Wgrav - Wfriction = Change in KE Wgrav = m*g(in x-direction)*(Change in height) -->(20kg)(9.81m/s^2*sin33)(3.5sin33m) Wfriction = (coefficient of friction)*m*g*distance -->(.2)(20kg)(9.81m/s^2)(3.5m) Change in KE = 0 Wman = 823.919J, but this is not right...what am i doing wrong?