Concept explainers
The forearm shown below is positioned at an angle
(a) What is the magnitude of the force that the biceps muscle exerts on the forearm for
(b) What is the magnitude of the force on the elbow joint for the same angle?
(c) How do these forces depend on the angle
Trending nowThis is a popular solution!
Chapter 12 Solutions
University Physics Volume 1
Additional Science Textbook Solutions
The Cosmic Perspective Fundamentals (2nd Edition)
Tutorials in Introductory Physics
The Cosmic Perspective (8th Edition)
Physics for Scientists and Engineers with Modern Physics
Conceptual Integrated Science
- A horizontal plank 4.00 m long and having mass 20.0 kg rests on two pivots, one at the left end and a second 1.00 m from the right end. Find the magnitude of the force exerted on the plank by the second pivot. (See Section 8.4.)arrow_forwardIn using the spring scale to find the equilibrant, why does one hold it horizontally on its body and not on its (topmost) handle?arrow_forwardA 68 kg man is in the prone position while during pushups. His feet and hands are 95 cm and 42 cm away respectively from his center of mass. What is the normal force exerted by on each (a) hand and (b) foot?arrow_forward
- the figure shows a horizontal human arm lifting a dumbbell. the forearm is in equilibrium under the action of the weight w of the dumbbell, the tension t in the tendon connected to the biceps muscle, and the force e exerted on the forearm by the upper arm at the elbow joints. we neglect the weight of the forearm itself. (for clarity, the point a where the tendon is attached is drawn farther from the elbow than its actual position.) given the weight w and the angle between the tension force and the horizontal, find t and the two components of ē (three unknown scalar quantities in all)arrow_forwardFind the x and y-coordinates of the center of gravity of a 4.00-ft by 8.00-ft uniform sheet of plywood with the upper right quadrant removed as shown in the figure below. Hint: The mass of any segment of the plywood sheet is proportional to the area of that segment.arrow_forwardA house painter is standing on a uniform, horizontal platform that is held in equilibrium by two cables attached to supports on the roof. The painter has a mass of 81.0 kg, and the mass of the platform is 22.0 kg. The distance from the left end of the platform to where the painter is standing is d = 2.00 m, and the total length of the platform is 5.00 m. How large is the force exerted by the left-hand cable on the platform?arrow_forward
- the anatomical structures in the lower leg and foot that are involved in standing on tiptoe, with the heel raised slightly off the floor so that the foot effectively contacts the floor only at point P. Assume distance a=-5.0 cm, distance b=15 cm, and the person’s weight W= 900 N. Of the forces acting on the foot, what are the (a) magnitude and (b) direction (up or down) of the force at point A from the calf muscle and the (c) magnitude and (d) direction (up or down) of the force at point B from the lower leg bones?arrow_forwardA person carries a plank of wood 2.0 m long with one hand pushing down on it at one end with a force F1 and the other hand holding it up at 50 cm from the end of the plank with force F2. f the plank has a mass of 19 kg and its center of gravity is at the middle of the plank, what is the force F2, in newtons? If the plank has a mass of 19 kg and its center of gravity is at the middle of the plank, what is the force F1, in newtons?arrow_forwardThe following figure represents a bicep curl maneuver where the center of mass (CoM) of a 23 kg dumbbell is 0.29 m from the elbow joint (pivot). The mass of the arm is 5 kg and acts 0.17 m from the elbow joint, and the biceps tendon acts at a distance of 0.01 m from the elbow joint. What is the required magnitude of the resultant joint reaction force (JRF) at the elbow in newtons (N) for the scenario described above in a) where static equilibrium is achieved.arrow_forward
- Two children of mass 15 kg and 35 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 3.0 m, at what distance, in meters, from the pivot point is the smaller child sitting in order to maintain the balance?arrow_forwardFind the force exerted by the biceps muscle in holding a 1.00-L milk carton (weight 9.90 N) with the forearm parallel to the floor. Assume that the hand is 35.0 cm from the elbow and that the upper arm is 30.0 cm long. The elbow is bent at a right angle, and one tendon of the biceps is attached to the forearm at a position 5.00 cm from the elbow, while the other tendon is attached at 30.0 cm from the elbow. The weight of the forearm and the empty hand is 16.9 N, and the center of gravity of the forearm with hand is at a distance of 16.5 cm from the elbow.arrow_forwardAs shown in the figure below, a stick of length L = 0.425 m and mass m = 0.225 kg is in contact with a rough floor at one end and a frictionless bowling ball (diameter d = 16.00 cm) at some other point such that the angle between the stick and the floor is ? = 30°. Determine the following. (a) magnitude of the force exerted on the stick by the bowling ballN(b) horizontal component of the force exerted on the stick by the floorN(c) vertical component of the force exerted on the stick by the floorNarrow_forward
- Physics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityCollege PhysicsPhysicsISBN:9781285737027Author:Raymond A. Serway, Chris VuillePublisher:Cengage Learning
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-Hill