2. Look at the diagram below. the smallest mass? pull a) spring balance pile of paper B D Which of the arrows, A, B, C or D, shows the direction of the frictional force when the pile of paper is pulled? b) The spring balance is used to measure the amount of force needed to pull the pile of paper along the table. Explain how the reading on the spring balance changes if the pile of paper is pulled along a: i) smoother surface, and ii) rougher surface. Is th fricti obje a​