A 55-kg box rests on a horizontal surface. The coefficient of static friction between the box and the surface is 0. 30, and the coefficient of kinetic friction is 0. 20. What horizontal force must be applied to the box to cause it to start sliding along the surface?.

Case # 51173878 weighs 814 pounds; case # 51173981 weighs 803 pounds; case # 51174058 weighs 817 pounds; case 51174178 weighs 815 pounds; case # 51174248 weighs 817 pounds; case # 51174495 weighs 781 pounds; case # 51174577 weighs 828 pounds. what are the case #'s of the two cases that weigh the same amount?