A crate of mass 200 kg is to be bright from a site on the ground floor to a third floor apartment. The workers know that they can either use the elevator first, their slide it along the third floor to the apartment, or first slide the crate to another location marked C below and then take the elevator to the third floor and slide it on the third floor a shorter distance. The trouble is that the third floor is very rough compared to the ground floor. Given that the coefficient of kinetic Motion between the crate and the ground floor is 0.100 and between the crate and the third floor surface is 0.300, find the work needed by the workers for each path shown from A to E. Assume that the force the workers need to do is just enough to slide the crate at constant velocity (zero acceleration). Note: The work by the elevator against the force of gravity is not done by the workers.
Want to see the full answer?
Check out a sample textbook solutionChapter 7 Solutions
University Physics Volume 1
Additional Science Textbook Solutions
College Physics
Tutorials in Introductory Physics
The Cosmic Perspective
The Cosmic Perspective (8th Edition)
Physics (5th Edition)
Cosmic Perspective Fundamentals
- The work done on an object is equal to the integral of the force on that object dotted with its displacent. This looks like W=∫(F.ds) (W is work, F is force, and ds is the infinitesimally small displacement vector). For a force whose direction is the line of motion, the equation becomes W=∫(Fdx). If the force on an object as a function of displacement is F(x)=3x2+x, what is the work as a function of displacement (using calculus application) W(x)? Assume W(0)=0 and the force is in the direction of the object's motion.arrow_forwardQ1/ The work done on an object is equal to the integral of the force on that object dotted with its displacent. This looks like W=[(F.ds) (W is work, F is force, and ds is the infinitesimally small displacement vector). For a force whose direction is the line of motion, the equation becomes W=[(Fdx). If the force on an object as a function of displacement is F(x)=3x2+x, what is the work as a function of displacement (using calculus application) W(x)? Assume W(0)=0 and the force is in the direction of the object's motion.arrow_forwardA particle of mass m is suspended from a ceiling through a string of length L. The particle moves in L 1/2 a horizontal circle of radius r such that r = speed of particle will be: .Thearrow_forward
- A mass m is placed at a height of h from the ground on a wedge . ( u coefficent of friction = 0 for mass and wedge , the mass moves down the wedge and travels at a distance of 20 m , u = 0.6 between ground and mass . Calculate the height h.arrow_forwardThe density of a star measured from the center of a star is equal to Z. a is constant. find the gravitational potential and g as a function of r.arrow_forwardOrnithologists have determined that some species of birds tend to avoid flights over large bodies of water during daylight hours. It is believed that more energy is required to fly over water than land because air generally rises over land and falls over water during the day. A bird with these tendencies is released from an island that is 4 km from the nearest point B on the shoreline, flies to a point C on the shoreline, and then flies along the shoreline to its nesting area D. Assume that the bird instinctively chooses a path that will minimize its energy expenditure. Points B andD are 9 km apart. (Round your answers to two decimal places.) island D. nest (a) In general, if it takes 1.2 times as much energy to fly over water as land, to what point C should the bird fly in order to minimize the total energy expended in returning to its nesting area? 6.1 x km from 8 (b) Let W and L denote the energy (in joules) per kilometer flown over water and land, respectively. Assuming the bird's…arrow_forward
- A satellite in Earth orbit has a mass of 102 kg and is at an altitude of 1.91 x 106 (Assume that U = 0 as r → ∞) What is the potential energy of the satellite–Earth system? What is the magnitude of the gravitational force exerted by the Earth on the satellite? What force, if any, does the satellite exert on the Earth? (Enter the magnitude of the force, if there is no force enter 0.)arrow_forwardA small plane, flying at 180 kph at an altitude of 240 m, is to drop an inflatable raft ti flood victims stranded on a flat roof. How far from the roof should the pilot release the package so that it will land on the roof?arrow_forwardPROBLEM 2 – The wooden block (mass m 0.54321 kg) is released from rest at A by a compressed spring (compressed length 0.6 m, undeformed length 1 m, spring constant k = 150 N/m). The block is allowed to slide through the rough horizontal surface (A to B), then along the smooth circular ramp (B to C, central angle 0 = 45.6°), until the block is released after point C. Calculate the speed of the block at points B and C. Also, what is the magnitude of the normal force exerted to the block just before the block leaves the ramp? Neglect the %3D geometry of the block. NOTE: Use Work-Energy Method to solve for the speeds; use FMA Method to compute for the normal force. Use g== 9.81 m/s = 32.2 ft/s? 0.6 m 1 m path of the block smooth surface B rough surface Hs = 0.35 A C Hx = 0.25 1.5 m 1.5 marrow_forward
- Show that the work done by the force field F=(y' – 2xyz")î+(3+2.xy – x*z')}+(6z° – 3x°yz*)& is path independent and calculate the work done by this force field in moving a particle from (1, -1, 2) to (2,3,1).arrow_forwardConsider two vectors A = 3.56 i + -3.07 k and B = 0.09 j + 1.82 k. Find the angle o between these two vectors. Express your answer in two decimal places.arrow_forwardB = (3.72 , 0, 0) and C = (−3.72, 0, 0) and connected to the ceiling at point A = (−4.50 , 4.03 , 5.00). D = (0, 3.15, 4.00) Force F is given by F=10.0 i−12.5 j+25.2 k N P has magnitude 50.0 N and direction angles α=110.0∘ β=29.5∘, and γ=69.3∘ for the x, y, and z axes, respectively. F= 10.0 i N-12.5 j N+ 25.2 k NP = -17.1 i N +43.5 j N + 17.7 k N Find the angle delta between F and Parrow_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