1–41.With a block and tackle the efforthas to move 125 feet in order toraise a load 25 feet.The frictionis so great that it takes a forceof 75 pounds to lift a load of 300pounds.The actual mechanicaladvantage is1.five2.two3.three4.four1-42.The theoretical mechanicaladvantage of a differential pulley,such as the one pictured in figure1M, depends upon the1.difference in diameters of thet w o t o p p u l l e ys2.sum of diameters of the two toppulleys3.length of the chain4.difference in diameters of thetwo small pulleys1-43.In the differential pulley picturedin figure 1M, if the radius of thesmall pulley at the top is 3inches, the radius of the largepulley at the top is 4 inches, andthe radius of the pulley at thebottom is 2 1/2 inches, thetheoretical mechanical advantage is1. 82. 93. 304. 361-44.Why is the actual mechanicaladvantage of the differentialpulley of textbook figure 2–11never so great as the theoreticalmechanical advantage of the pulley?1.Part of the effort applied tothe chain is used to overcomethe frictional resistance ofthe pulley’s moving parts2.The diameter of C is betweenthose of A and B3.The diameter of A is greaterthan that of B4.The length of the chain feddown is greater than the lengthof the chain fed up1-45.A wheel and axle can rotateclockwise or counterclockwise aboutan axis to provide a mechanicaladvantage or an increase in speed.1.True2.False1-46.The mechanical advantage of a wheeland axle depends upon the1.amount of force applied and thesize of the wheel2.size of the wheel and theamount of the resistance3.ratio of the radius of thewheel to which force is appliedto the radius of the axle onwhich it turns4.length of the axle7