Free body diagram N F F. N F. Figure 5.15 (a) What is the mechanical advantage of a nail puller--similar to the one shown in Figure 5.15--where you exert a force 45.0 cm from the pivot and the nail is 1.85 cm on the other side? (b) What minimum force must you exert to apply a force of 1250 N to the nail?

NEED IN RUSH! A transmission tower is held in place by bolts at B, C, and D. If the force on the cable AD is 664 N, what is the angle of orientation with respect to the x-axis and y-axis of the wire in bolt D (θD.x and θD.y)? (degrees) Given: y = 20 m XB = XD = 2.4 m ; Xc = 8.3ZB = 4.2 m ; ZC = 2.3 m ; ZD = 10.2 m

4-7. Are the following statements true or false? (a) The efficiency of a refrigerator is inversely proportional to the temperature difference between indoors and outdoors. (b) The efficiency of an automobile is inversely proportional to the temperature difference between the engine and the outside air. (c) The efficiency of a heat pump is directly proportional to the temperature difference between indoors and outdoors. (d) One of the key energy conversion devices in an electric power plant converts work to heat. (e) One of the key energy conversion devices in an automobile converts heat to work. (f) The efficiency of conversion of heat to work is typically higher than the efficiency of conversion of work to heat.