3) (A) 3,00 m The section AB is frictionless. There is friction only between B to C is a horizontal span 6 m long with a friction coefficient of kinetic friction k = 0.20. A block of mass 10 kg is thrown with an initial speed of 5 m/s. After sliding on the on the track, it compresses the spring by the 0.4 m. a) Calculate the thermal energy produced by the as the block slides from B to C. (5 points) b) Calculate the stiffness constant k for the spring. (15) points). (g = 9.80 m/s) TRA (99) 6,00 m