lf G is part of weight of each load camed by each roller and uo the kinetic coefficient of friction, the frictional sliding force between the load and roller during time t is -Guo and the work done by the load BG'kyt' where v linear velocity of the load, and vt is the distance moved by the load in time t', represented by the area oEAF in Fig. 6.6.7. The distance travelled by any point on the periphery of the roller during this time will be t'area OAF, which is also the sliding path. This shows that half of the work done by load is spent in overcoming the friction, and the other half is used in imparting kinetic energy to the roller. 1 w If w' is the weight of the rotating part of the roller, then its kinetic energy Where q is a factor of value between 0.8 to 0.9, because not all the mass of the roller moving parts is on the periphery, and thereby not moving with velocity v. Therefore, the work done due to sliding and acceleration of one roller is given by