QUESTIONS 1. In the drawing to the right, a 90.0 cm long metal bar having a mass of 0.500 kg is supported by two strings as shown. a) Determine the value of the tension in each string. 60° 80 16° b) Calculate the position of the center of mass from the left end of the torque bar.

ASK YOUR TEACHER PRACTICE ANOTHER The chewing muscle, the masseter, is one of the strongest in the human body. It is attached to the mandible (lower jawbone) as shown in figure (a). The jawbone is pivoted about a socket just in front of the auditory canal. The forces acting on the jawbone are equivalent to those acting on the curved bar in figure (b). DETAILS SERCP11 8.3.P.033. Mandible magnitude of R magnitude of Masseter Need Help? -7.50 cm - 3.50 cm is the force exerted by the food being chewed against the jawbone, is the force of tension in the masseter, and is the force everted by the socket on the mandible. Find and i (in N) for a person who bites down on a piece of steak with a force of 53.5 N MY NOTES

Two children of mass 21 kg and 26 kg sit balanced on a seesaw with the pivot point located at the center of the seesaw. If the children are separated by a distance of 2 m, at what distance from the pivot point is the small child sitting in order to maintain the balance? m

The fishing pole in the figure below makes an angle of 20.0° with the horizontal. What is the magnitude of the torque exerted by the fish about an axis perpendicular to the page and passing through the angler's hand if the fish pulls on the fishing line with a force F = 125 N at an angle 37.0° below the horizontal? The force is applied at à point L = 1.92 m from the angler's hands. N.m -I 20.0° 37.0 1 20.0° F

Two kids are on a uniform seesaw supported at its center. The kid is on the right side of the seesaw has a mass m kg and is at a distance 1.59 from the center of the seesaw. The kid is on the left side of the seesaw has a mass 30.8 kg and is at a distance 1.49 from the center of the seesaw. The seesaw is in static equilibrium. What is the mass m in kg? Give your answer to three significant figures.

In exercise physiology studies, it is sometimes important to determine the location of a person's center of gravity. This can be done with the arrangement shown in the figure below. -2.00 m A light plank rests on two scales that read F 91 = 440 N and F 92 = 320 N. The scales are separated by a distance of 2.00 m. How far from the woman's feet is her center of gravity? m

The uniform seesaw shown below is balanced on a fulcrum located d1 = 3.5m from the left end. The bigger boy on the left end has a mass m1 =75 kg. The smaller boy on the right end has a mass of m2 = 55 kg and is a distance d2 = 4.5 m from the fulcrum. The mass of the board is mb.    Draw all forces acting on the seesaw board showing their directions and locations. Where would you draw the weight of the board? Identify and show the direction of rotations caused by the torques provided by all forces about the fulcrum. If the seesaw is in static equilibrium, write down the two conditions of static equilibrium symbolically using the forces and distances in the figure. Solve for the mass of the board. Calculate the force of fulcrum on the board.

3.) Consider the drawing below: Ť The 4.0-kg hinged rod is uniform and has a = 2.0m. The object at the end of the rod masses 8.0-kg. A wire affixed to the wall holds the rod horizontally. The wire makes an angle of 28° with the rod. a. Draw a picture. b. Draw a free-body diagram centered at the top of the loop. c. Use equilibrium considerations to determine the tension in the wire and the x and y forces on the rod's hinge.

3. Consider two thin-walled beams of the same wall thickness with cross- sections as shown in Figure 2. Applied torque is the same for both beams. Beams are twisted such that twisting angles are equal to each other. Find the relation between R2 and R₁ for the case = π/3. What will be this relation if we double the center angle o? R₁ R₁ R₂ FIGURE 2. Cross-sections of two thin-walled beams.