This PhysCast is going to analyse a problem of two connecting blocks using the work-kinetic energy theorem.. A 5.0 kg block is hanging by a string connected to a 3.0 kg mass via a massless pulley. The 3.0 kg mass sits on a flat table with a co-efficient of kinetic friction of 0.40. Starting from rest, what is the speed of the 5.0 kg mass when it has fallen 1.50 m?