Two children sitting on a sled at rest in the snow ask you to pull them. You oblige by pulling on the sled's rope, which makes an angle of 40e with the horizontal (Figure 5-7). The children have a combined mass of 51 kg and the sled has a mass of 5.5 kg. The coefficients of static and kinetic friction are H. =0.19 and Hk= O.05. Calculate the frictional force exerted by the ground on the sled if the tension in the rope is 128 N. (Take g-9.81 m/s2. 2% of error will be tolerated in your answers.) 24