Concept explainers
a) What is the mechanical advantage of a wheelbarrow, such as the one in Figure 9.24, if the center of gravity of the wheelbarrow and its load has a perpendicular lever arm of 5.50 cm, while the hands have a perpendicular lever arm of 1.02 m? (b) What upward force should you exert to support the wheelbarrow and its load if their combined mass is 55.0 kg? (c) What force does the wheel exert on the ground?
Figure 9.24 (a) In the case of the wheelbarrow, the output force or load is between the pivot and the input force. The pivot IS the wheel's axle. Here, the output force is greater than the input force. Thus, a wheelbarrow enables you to lift much heavier loads than you could with your body alone. (b) In the case of the shovel, the input force is between the pivot and the load, but the input lever arm is shorter than the output lever arm. The pivot is at the handle held by the right hand. Here, the output force (supporting the shovel's load) is less than the input force (from the hand nearest the load), because the Input is exerted closer to the pivot than is the output
Trending nowThis is a popular solution!
Learn your wayIncludes step-by-step video
Chapter 9 Solutions
College Physics
Additional Science Textbook Solutions
University Physics Volume 1
Conceptual Physics (12th Edition)
Physics for Scientists and Engineers: A Strategic Approach with Modern Physics (4th Edition)
University Physics with Modern Physics (14th Edition)
Tutorials in Introductory Physics
College Physics: A Strategic Approach (4th Edition)
- What three factors affect the torque created by a force relative to a specific pivot point?arrow_forwardA 70 kg man’s arm, including the hand, can be modeled as a 75-cm-long uniform cylinder with a mass of 3.5 kg. In raising both his arms, from hanging down to straight up, by how much does he raise his center of gravity?arrow_forwardA uniform bridge span weighs 50 103 N and is 40.0 m long. An automobile weighing 15 103N is parked with its center of gravity located 12.0 m from the right pier. Where is the center of mass of the bridge-automobile combination located as measured from the left pier?arrow_forward
- In Figure 10.17, the Achilles tendon exerts a force F = 720 N. What is the torque it exerts about the ankle joint?arrow_forwardThe fishing pole in the figure makes an angle of 20.0o with the horizontal. What is the torque exerted by the fish about an axisperpendicular to the page and passing through the angler’s hand if the fish pulls on the fishing line with a force of 100 N at anangle 37.0o below the horizontal? The force is applied at a point of 2.00 m from the angler’s hands.arrow_forwardA sculpture is 4.00 m tall and has its center of gravity located 1.80 m above the center of its base. The base is a square with a side of 1.10 m. To what angle, theta, can the sculpture be tipped before it falls over?arrow_forward
- A heavy concrete panel is being lifted into position in a building by means of a crane (see figure below). The tension of 1.02 104 N in the supporting cable produces a torque with respect to point O. (Let L = 17.9 m.) Find the torque. (Its not 10.973 x 104)arrow_forwardA car manufacturer claims that you can drive its new vehicle across a hill with a 47° slope before the vehicle starts to tip. If the vehicle is 2.0 m wide, how high is its center of gravity?arrow_forwardA uniform plank of length 5 m and weight 200 N rests horizontally on two supports with 1.1 m of the plank hanging over the right support. To what distance x, can a person who weights 430 N walk on the overhanging part of the plank before it just starts to tip? What is the net torque around the pivot point (take the FR support as the pivot point)?arrow_forward
- The boom of a crane is 19.56 m long and is inclined 28.4 degrees from the horizontal. A bucket of cement with a mass of 3292.29 kg is suspended from the upper end of the boom. What is the torque acting on the point where the boom is attached to the crane?arrow_forwardA small 1000-kg SUV has a wheel base of 3.0 m. If 60% if its weight rests on the front wheels, how far behind the front wheels is the wagon’s center of mass?arrow_forwardThe two ends of the barbell shown are made of the same material. Which of the points shown is at the barbell’s center of gravity?arrow_forward
- Glencoe Physics: Principles and Problems, Student...PhysicsISBN:9780078807213Author:Paul W. ZitzewitzPublisher:Glencoe/McGraw-HillUniversity Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University