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In this diagram the pulleys are smooth. the strings light and the table is rough. Block A has a mass of 10 kg- Objects R and 8 have masses of 4 kg and 6 kg respectively. The block is just about to slip. R a) What is the direction of the frictional force acting on A? b) Draw a fully labelled diagram showing the forces acting when the block isjust about to slip. c} What is the size of the frictional force when the block is just about to slip