1. A light horizontal spring has a force constant of k=100 N/m. A 2.00 kg block is pressed against one end of the spring, compressing it 0.100 m. When the block is released from rest it moves 0.250 m to the right of release position. Show that the coefficient of kinetic friction between the block and the horizontal surface is 0.102.
2. Two blocks, A and B (with mass 50kg and 100kg respectively) are connected by a string as shown in the attached picture. The pulley is frictionless and of negligible mass. The coefficient of kinetic friction between block A and the incline is 0.25. Determine the change in kinetic energy of block A as it moves from C to D, a distance of 20 m up the incline if the system starts from rest.
In the equation for kinetic energy 'u; stands for velocity of the block ...
These two problems involving friction give an insight into the effect friction has on a spring problem and an inclined plane problem.