Concept explainers
A 75 kg window cleaner uses a 10 kg ladder that is 5.0 m long. He places one end on the ground 2.5 m from a wall, rests the upper end against a cracked window, and climbs the ladder. He is 3.0 m up along the ladder when the window breaks. Neglect friction between the ladder and window and assume that the base of the ladder does not slip. When the window is on the verge of breaking, what are (a) the magnitude of the force on the window from the ladder, (b) the magnitude of the force on the ladder from the ground, and (c) the angle (relative to the horizontal) of that force on the ladder?
Trending nowThis is a popular solution!
Chapter 12 Solutions
Fundamentals of Physics Extended
Additional Science Textbook Solutions
Microbiology: An Introduction
Cosmic Perspective Fundamentals
Microbiology: An Introduction
Introductory Chemistry (6th Edition)
Human Anatomy & Physiology (2nd Edition)
Chemistry: The Central Science (14th Edition)
- You have a summer job working downtown washing windows on skyscrapers (the pay is great and so are the medical benefits). The platform you and your partner are using to get to the windows is a meter wide and four meters long. You know from hauling the platform out of your truck countless times that it has a mass of 70 kg. It is supported by two cables, one at each end, mounted on-center to prevent the platform from tipping over as it is pulled up the side of the building at a constant speed. If you (mass of 55 kg) are standing on the platform 1 meter from one cable while your partner (mass of 87 kg) is 1.3 meters from the other cable and both of you are half a meter from the side, what is the tension in each cable? Assume the platform has a uniform mass distribution and is of negligible thickness.arrow_forwardI need help with this Hw Problem.arrow_forwardA uniform 5.0 m long 25 kg plank is to hold two people washing windows on a downtown skyscraper. The plank is supported by a rope at each end, and each of the ropes has a breaking point of 1200 N (the maximum tension allowed before the rope breaks). If the mass of the window washer that is standing 1.0 m from the right end of the plank is 85 kg and the second window washer with a mass of 75 kg stands 2.0 m from the left end of the plank, then what are the magnitudes of the tensions in each rope? Do either of the ropes break? Include a force or free-body diagram of the situation.arrow_forward
- A 6 m long board is held up at each end by a vertical rope. Assume the board has negligible mass. A 60 kg box sits 4 m from the left end. Find the tension in the rope on the right.arrow_forwardA 30 ft ladder, weighing 100 lbs having its center of mass one-third of the way up from the bottom, rests against a smooth wall so that it makes an angle of 60° with the ground. If the coefficient of friction between the ground and the ladder is 0.4, how high can a 150-lb man go before the ladder slips?arrow_forwardAfrican elephants are the largest land animals. They consume approximately 10% of their body weight in food each day, which for an adult male, can be 1000 lb. of vegetation! Their diet consists mostly of grasses, bamboo, tree bark, and fruit. They also like to dine on tree leaves. To reach them, they often stand up on their hind legs and extend their trunks (see the figure). The elephant in the figure is in equilibrium. The location of the elephant's center of mass is shown, and the axis of rotation has been chosen to correspond to the hip joint. The forces in the elephant's free-body diagram are shown, and there is a static friction force between the elephant's back feet and the ground. Use the following information and calculate the magnitude of the tension in the elephant's trunk T (m = 4540 kg, FN = rfs = 133 cm, rcg = 76.0 cm, r = 229 cm). Number +x Axis of rotation Units 60 165 30 W TTFN cg 10° Michael Poliza/Caters News Agencyarrow_forward
- A 2.4 m ladder rests on a vertical wall as shown in the figure. The ladder has 7 rungs and the rungs are spaced 0.30 m apart, and the top and bottom rungs are 0.30 m from their respective ends of the ladder. Surfaces at A and B both have the same coefficient of friction. If a worker weighs 360 N and stands on the middle rung, determine the minimum value of the coefficient of friction so that the ladder does not slide. Neglect the weight of the ladder.arrow_forwardA 200 N ladder that is 9.0 m long leans against a frictionless wall. There is friction between the ladder and the floor. A rope is attached to the ladder at a point 3 m above the bottom of the ladder (one third of the way up the ladder). It is pulled horizontally to the left with a tension of 25 N. If the coefficient of friction between the floor and the ladder is .67, what is the smallest angle the wall can make with the floor before it begins to slide down the wall.arrow_forwardA 30 foot ladder weighing 100 lbs having its center of mass one-third of the way up from the bottom rests against a smooth wall so that it makes an angle of 60 degrees with the ground. If the coefficient of friction between the ground and the ladder is 0.4, how high can a 150-lb man go before the ladder slips.arrow_forward
- A 9 m long board that has a mass of 14. Each end is held up by a vertical rope. A 45 kg box sits 1 m from the left end. Find the tension in the rope on the right. Hint: With forces applied at different places, this is a beam problem pick a pivot point measure all distances from the pivot point Apply Στ = 0 Don't forget torque = force x dist, so you need to multiply the masses by g = 9.8 m/s2 If you need more information, apply ΣF = 0arrow_forwardA 20 kg dog stands on a 40 kg platform that is supported by two ropes. One rope is attached to the right edge of the platform and the other is attached 50 cm from the left edge of the platform. The dog sits 50 cm from the right edge of the platform. A 5.0 kg cat jumps up, but is wary of the dog abs stays all the way on the left edge. The platform is 2.0 m long. What is the tension in each rope?arrow_forwardA uniform ladder 18 ft long and weighing 120 lbs rests against a smooth wall. The angle between the ladder and the ground is 70°. The coefficient of friction between the ground and the ladder is 0.25. How far up the ladder can a 180 lb man walk before the ladder slips?arrow_forward
- College PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningUniversity Physics (14th Edition)PhysicsISBN:9780133969290Author:Hugh D. Young, Roger A. FreedmanPublisher:PEARSONIntroduction To Quantum MechanicsPhysicsISBN:9781107189638Author:Griffiths, David J., Schroeter, Darrell F.Publisher:Cambridge University Press
- Physics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningLecture- Tutorials for Introductory AstronomyPhysicsISBN:9780321820464Author:Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina BrissendenPublisher:Addison-WesleyCollege Physics: A Strategic Approach (4th Editio...PhysicsISBN:9780134609034Author:Randall D. Knight (Professor Emeritus), Brian Jones, Stuart FieldPublisher:PEARSON