51. A 2.8kg hanging sandbag is connected by a string over a frictionless pulley to the 5.6-rkg box on a table. The coefcient of kinetic friction between the box and the table is 0.24. Ignore the masses of the string and the pulley. ' a) Find the acceleration of the box. b} Find the tension in the vertical string. c) When 5.6-kg box is replaced with another box, the box and the sandbag do not more. Find the minimum mass of the new box. 52. An object starts from rest and slides 7.0 m along a frictionless slope in 1.2 s as shown in the diagram. 7.0 m a) What angle does the slope make with the horizontal? b) What is the acceleration of the object