Concept explainers
In an emergency situation, a person with a broken forearm ties a strap from his hand to clip on his shoulder as in Figure P8.92. His 1.60-kg forearm remains in a horizontal position and the strap makes an angle of θ = 50.0° with the horizontal. Assume the forearm is uniform, has a length of ℓ = 0.320 m, .assume the biceps muscle is relaxed, and ignore the mass and length of the hand. Find (a) the tension in the snap and (b) the components of the reaction force exerted by the humerus on the forearm.
Figure P8.92
Trending nowThis is a popular solution!
Chapter 8 Solutions
College Physics
Additional Science Textbook Solutions
College Physics
Fundamentals Of Physics - Volume 1 Only
Physical Science
College Physics: A Strategic Approach (3rd Edition)
Physics: Principles with Applications
Physics for Scientists and Engineers
- A bridge of length 50.0 m and mass 8.00 104 kg is supported on a smooth pier at each end as shown in Figure P12.25. A truck of mass 3.00 104 kg is located 15.0 m from one end. What are the forces on the bridge at the points of support? Figure P12.25arrow_forwardA 10.0-kg monkey climbs a uniform ladder with weight 1.20 102 N and length L = 3.00 m as shown in Figure P12.14. The ladder rests against the wall and makes an angle of = 60.0 with the ground. The upper and lower ends of the ladder rest on frictionless surfaces. The lower end is connected to the wall by a horizontal rope that is frayed and can support a maximum tension of only 80.0 N. (a) Draw a force diagram for the ladder. (b) Find the normal force exerted on the bottom of the ladder. (c) Find the tension in the rope when the monkey is two-thirds of the way up the ladder. (d) Find the maximum distance d that the monkey can climb up the ladder before the rope breaks. (e) If the horizontal surface were rough and the rope were removed, how would your analysis of the problem change? What other information would you need to answer parts (c) and (d)? Figure P12.14arrow_forwardA uniform beam resting on two pivots has a length L = 6.00 m and mass M = 90.0 kg. The pivot under the left end exerts a normal force n1 on the beam, and the second pivot located a distance = 4.00 m from the left end exerts a normal force n2. A woman of mass m = 55.0 kg steps onto the left end of the beam and begins walking to the right as in Figure P10.28. The goal is to find the womans position when the beam begins to tip. (a) What is the appropriate analysis model for the beam before it begins to tip? (b) Sketch a force diagram for the beam, labeling the gravitational and normal forces acting on the beam and placing the woman a distance x to the right of the first pivot, which is the origin. (c) Where is the woman when the normal force n1 is the greatest? (d) What is n1 when the beam is about to tip? (e) Use Equation 10.27 to find the value of n2 when the beam is about to tip. (f) Using the result of part (d) and Equation 10.28, with torques computed around the second pivot, find the womans position x when the beam is about to tip. (g) Check the answer to part (e) by computing torques around the first pivot point. Figure P10.28arrow_forward
- In an emergency situation, a person with a broken forearm ties a strap from his hand to clip on his shoulder as in the figure below. His 1.60-kg forearm remains in a horizontal position and the strap makes an angle of 0 = 53.5° with the horizontal. Assume the forearm is uniform, has a length of e = 0.324 m, assume the biceps muscle is relaxed, and ignore the mass and length of the hand. R (a) Find the tension in the strap. (b) Find the components of the reaction force exerted by the humerus on the forearm. (Assume the positive x-direction is to the right and the positive y-direction is upward.) Ry = N R, = Narrow_forwardIn an emergency situation,a person with a broken forearmties a strap from his hand to clipon his shoulder as in Figure P8.92.His 1.60-kg forearm remains in ahorizontal position and the strapmakes an angle of θ = 50.0° withthe horizontal. Assume the forearmis uniform, has a length ofl= 0.320 m, assume the bicepsmuscle is relaxed, and ignore themass and length of the hand. Find(a) the tension in the strap and(b) the components of the reactionforce exerted by the humeruson the forearm.arrow_forwardThe bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass 2.25 kg and a length of 0.425 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 7.35 kg so that her forearm remains motionless, what is the force F exerted by the biceps muscle? Image is attached below. Please show all work.arrow_forward
- A 72.0-kg weightlifter doing arm raises holds a 7.50-kg weight. Her arm pivots around the elbow joint, starting 40.0° below the horizontal (Fig. P11.54). Biometric measurements have shown that, together, the forearms and the hands account for 6.00% of a person’s weight. Since the upper arm is held vertically, the biceps muscle always acts verti-cally and is attached to the bones of the forearm 5.50 cm from the elbow joint. The center of mass of this person’s forearm–hand combination is 16.0 cm from the elbow joint, along the bones of the forearm, and she holds the weight 38.0 cm from her elbow joint. (a) Draw a free-body diagram of the forearm. (b) What force does the biceps muscle exert on the forearm? (c) Find the magni-tude and direction of the force that the elbow joint exerts on the forearm. (d) As the weightlifter raises her arm toward a horizontal position, will the force in the biceps muscle increase, decrease, or stay the same? Why? Solve A B C D and show complete solutionarrow_forwardThe bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Biceps muscle Assume the forearm has a mass of 2.25 kg and a length of 0.425 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to Humerus hold an object of mass 6.55 kg so that her forearm remains motionless, what is the force exerted by the biceps muscle? Radius Elbow. Ulna force: N Handarrow_forwardThe bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.35 kg and a length of 0.445 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 6.15 kg so that her forearm remains motionless, what is the force F exerted by the biceps muscle? 5 Humerus. F= Elbow. Biceps muscle Radius Ulna Hand Narrow_forward
- The bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.35 kg and a length of 0.445 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 6.15 kg so that her forearm remains motionless, what is the force exerted by the biceps musclearrow_forwardThe bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.45 kg and a length of 0.465 m. When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 5.35 kg so that her forearm remains motionless, what is the force F exerted by the biceps muscle? F=?arrow_forwardThe bones of the forearm (radius and ulna) are hinged to the humerus at the elbow. The biceps muscle connects to the bones of the forearm about 2.15 cm beyond the joint. Assume the forearm has a mass of 2.35 kg and a length of 0.445 m.When the humerus and the biceps are nearly vertical and the forearm is horizontal, if a person wishes to hold an object of mass 4.95 kg so that her forearm remains motionless, what is the force exerted by the biceps muscle?arrow_forward
- College PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning