. A small disk of radius R1 is mounted coaxially with a larger disk of radius R2. The disks are securely fastened to each other and the combination is free to rotate on a fixed axle that is perpendicular to a horizontal table top. A string is wrapped around the larger disk and attached to a block of mass m, on the table. Another string is wrapped around the smaller disk and is pulled with a force F as shown. If there is friction between the table and the block only, the minimum value for the coefficient of friction so that the block does not move is given by, (a) = R1 R2 F mg (b) = R2 2 R1 F mg (c) = R1 R2 mg F (d) = R2 R1 F mg (e) = (1 R1 R2 ) F mg