1. The problem statement, all variables and given/known data 80kg box is on a 20 degree incline against a spring and is released from rest. Coefficient of static friction is .25. Determine max and in values of the intial compression force in the spring so that block will not slip on release. Then calculate the magnitude and direction of friction acting on the block if the spring compression force is 200N 2. Relevant equations FBD: http://i57.tinypic.com/2hs7orr.png (80kg)*(9.81m/s^2) = 784.8N Fnormal = (784.8 N) *(cos20) = 737.47 N Fwparallel = 784.8sin20 = 268.42 N Fwperpendicular = 784.8 * cos20 = 737.47 N Ffriction = (268.42)*(.25) = 67.11N 3. The attempt at a solution See 2 I'm not sure where to go with the spring. Don't we need a spring constant for this?