1. The problem statement, all variables and given/known data A block of mass 1.6 kg is attached to a horizontal spring that has a force constant 900 N/m. The spring is compressed 2.0 cm and is then released from rest. a) A constant friction force of 3.8 N retards the block's motion from the moment it is released. At what position x of the block is its speed a maximum? m=1.6kg K=900 N/m Friction=3.8N s=2cm 2. Relevant equations PE=.5Kx^2 (elastic potential energy function from the spring) KE=.5mv^2 PE[a]+KE[a]=PE+KE, where [a] is the initial position of the question, and is where the position of x. 3. The attempt at a solution Since [a] is the initial position, then the equation that I wrote above will get rid of KE[a], since there is no Kinetic energy involved (It is at rest). Furthermore, at , it will get rid of PE because when finding the speed is max, PE is zero and KE is at the max. That being said, what throws me off is the friction that slows down the block after it is released. So my next guess was since we got rid of KE[a] and PE, I put the equations accordingly like this: .5Kx^2=.5mv^2 But I dont know where to apply the Friction given.