Determine the magnitude P of the vertical force re- quired to lift the wheelbarrow free of the ground at point B. The combined weight of the wheelbarrow and its load is 240 lb with center of gravity at G. A 24" 20" B 19" 21" 8"

(II) (a) What is the maximum tension possible in a1.00-mm-diameter nylon tennis racket string? (b) If youwant tighter strings, what do you do to prevent breakage:use thinner or thicker strings? Why? What causes stringsto break when they are hit by the ball?

17-45. The drop gate at the end of the trailer has a mass of 1.25 Mg and mass center at G. If it is supported by the cable AB and hinge at C, determine the tension in the cable when the truck begins to accelerate at 5 m/s?. Also, what are the horizontal and vertical components of reaction at the hinge C? 30 1.5 m 45°

(3) A body of mass 8 kg is suspended by two light inextensible strings inclined at the angles shown in the diagram below. Find the tension in the tendons when the object is in equilibrium.

- 5. Two identical, uniform beams of length 3 m and weighing 260 N each are connected at one end by a frictionless hinge. A light horizontal crossbar, attached at the midpoints of the beams maintains an angle 50° between the beams. The beams are suspended from the ceiling by vertical wires so they form a V. See figure. (a) What force does the crossbar exert on each beam? (b) Is the crossbar under compression or tension, i.e. are the ends of the crossbar being pushed together or stretched farther apart? (c) What force (magnitude and direction) does the hinge exert on each beam? Crossbar Hinge

A 90-m wire is suspended between two points at the same elevation that are 60 m apart. Knowing that the maximum tension is 300 N, determine (a) the sag of the wire, (b) the total mass of the wire.

(II) Figure 9–50 shows a pair of forceps used to hold a thin plastic rod firmly. If the thumb and finger each squeeze with a force Fr = FF = 11.0 N, what force do the forceps jaws exert on the plastic rod? Jaws Rod Fr P FIGURE 9-50 8.50 cm 2.70 cm Problem 6.

(II) A 110-kg horizontal beam is supported at each end.A 320-kg piano rests a quarter of the way from one end.What is the vertical force on each of the supports?

26. (III) Two wires run from the top of a pole 2.6 m tall that supports a volleyball net. The two wires are anchored to the ground 2.0 m apart, and each is 2.0 m from the pole (Fig. 9–66). The tension in each wire is 115 N. What is the tension in the net, assumed horizontal and attached at the top of the pole? \2.0 m -2.0 m FIGURE 9-66 Problem 26. 2.6 m 2.0 m-