Question

A 2.95 kg block on a horizontal floor is attached to a horizontal spring that is initially compressed 0.0330 m. The spring has force constant 900 N/m. The coefficient of kinetic friction between the floor and the block is 0.42 . The block and spring are released from rest and the block slides along the floor.
What is the speed of the block when it has moved a distance of 0.013 m from its initial position? (At this point, the spring is compressed 0.0200m.)

Answer 1

Try using conservation of energy. Don't forget the frictional work term. There will be a change in the potential energy of the compressed spring.