Two horses pull a large crate at constant speed across a barn floor by means of two light steel cables. A large box of mass 250 kg sits on the crate. As the horse pull, the cables are parrallel to the horizontal floor. The coefficient of friction between the crate and the barn floor is 0.25. a) What is the work done by each horse if the box is moved a distance of 25m? b) What is the tension in each cable if the angle between each cable and the direction the crate moves is 15 degree?