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BIO When a gymnast performing on the rings executes the iron cross, he maintains the position at rest shown in Figure P10.85a. In this maneuver, the gymnast’s feet (not shown) are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi (“lats”) and the pectoralis major (“pecs”). One of the rings exerts an upward fore
Figure P10.85
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Chapter 10 Solutions
Principles of Physics: A Calculus-Based Text
- Children playing pirates have suspended a uniform wooden plank with mass 15.0 kg and length 2.50 m as shown in Figure P14.27. What is the tension in each of the three ropes when Sophia, with a mass of 23.0 kg, is made to walk the plank and is 1.50 m from reaching the end of the plank? FIGURE P14.27arrow_forwardUnlike most of the other muscles in our bodies, the masseter muscle in the jaw, as illustrated in the figure, is attached relatively far from the joint, enabling very large forces to be exerted by the back teeth. This is shown in the figure below, where a person is biting down on a bullet placed between the back teeth. (FM= 210 N and rR = 4.1 cm.) (a) Using the information in the figure, calculate the magnitude of the force exerted by the teeth on the bullet. (b) Calculate magnitude of the force on the joint.arrow_forwardWhen a gymnast performing on the rings executes the iron cross, he maintains the position at rest shown in the figure at the top. In this maneuver, the gymnast's feet (not shown) are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi ("lats") and the pectoralis major ("pecs"). One of the rings exerts an upward force F½ on a hand as shown in the figure at the bottom. The force F¸ is exerted by the shoulder joint on the arm. The latissimus dorsi and pectoralis major muscles exert a total force Fm on the arm. Ed Bock/CORBIS Shoulder joint 4.00 cm- F π/4 F 70.0 cm (a) Using the information in the figure, find the magnitude of the force Fm. (Use only scalar quantities, i.e. Få for Ƒn| entered in meters, but do not include the units themselves. Any angles should be entered in radians, not degrees.) Fh = Fmcos(x) and Fs for Fs. Use any variable or symbol stated above as necessary. Any lengths should bearrow_forward
- When a gymnast weighing 740 N executes the iron cross as in figure (a), the primary muscles involved in supporting this position are the latissimus dorsi ("lats") and the pectoralis major ("pecs"). The rings exert an upward force on the arms and support the weight of the gymnast. The force exerted by the shoulder joint on the arm is labeled F while the two muscles exert a total force F on the arm. Determine the magnitude of the force F Note that one ring supports half the weight of the gymnast, which is w 370 N as indicated in figure (b). Assume that the force F acts at an angle of 45° below the horizontal at a distance of 4.0 cm from the shoulder joint. In your estimate, take the distance from the shoulder joint to the hand to be L = 75 cm and ignore the weight of the arm. m kN Shoulder joint 4.0 cm- 45.00 Ed Bock/CORBISarrow_forwardScientists have studied how snakes grip and climb ropes. In one study, they found that an important characteristic of a rope is its “compliance”— that is, how easily the rope, while under tension, can be flexed. As shown how scientists measured a rope’s compliance by attaching it to two strings, each supporting an identical mass m. The strings contort the rope so that its middle section lies at angle θ. For θ = 30° and m = 100 g, what are the tensions T1 and T2 in the upper and middle parts of the rope?arrow_forwardWhen a gymnast performing on the rings executes the iron cross, he maintains the position at rest shown in figure (a). In this maneuver, the gymnast’s feet are off the floor. The primary muscles involved in supporting this position are the latissimus dorsi (“lats”) and the pectoralis major (“pecs”). One of the rings exerts an upward force Fh on a hand as shown in figure (b). The force Fs is exerted by the shoulder joint on the arm. The lats and pecs major muscles exert a total force Fm on the arm. Using the information in the figure, find the magnitude of the force Fm for an athlete of weight 750 N. Hint Fh = 750/2 N.arrow_forward
- A gate is held in the position shown by cable AB. If the tension in the cable is 7.10 kN, determine the moment Mo made by the tension (as applied to point A) about the pivot point O of the gate. B 0.17 m A 6.7 m 6.1 m 0658 0.16 m 2.1 m Answer: Mo = i i+ i j+ i k)kN-marrow_forwardIf the allowable bending stress is 0 = 218 MPa, find the magnitude of the maximum internal bending moment M₂ that can be supported by the beam. The moment of inertia about the z axis is 402,238,667 mm4. 16 mm 240 mm V O 698 kN-m O 501 kN-m O 579 kN-m O 651 kN-m O 461 kN-m 30 mm 350 mmarrow_forwardScientists have studied how snakes grip and climb ropes. In one study, they found that an important characteristic of a rope is its "compliance"--that is, how easily the rope, while under tension, can be flexed. (Figure 1) shows how scientists measured a rope's compliance by attaching it to two strings, each supporting an identical mass mm. The lower part of the rope is held under tension by a spring (not shown). The strings contort the rope so that its middle section lies at angle θ. For θ = 45∘ and mm = 400 g, what is the tension T2 in the middle part of the rope?arrow_forward
- Please solve this correctlyarrow_forwardB9arrow_forwardAs a swimmer pulls his arm through the water, various muscles exert forces on the upper arm. The figure below shows a force F exerted on the humerus (upper arm bone) by the pectoral muscle. The muscle is connected to the bone d = 7.10 cm from the center point O of the shoulder joint. Find the magnitude of F, if this force's torque on the arm provides half of the total torque balancing the torque produced by the water pushing against the hand. (Let Fhand = 108 and D = 33.0 cm. ) please solve thank youarrow_forward
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