Physics Fundamentals
2nd Edition
ISBN: 9780971313453
Author: Vincent P. Coletta
Publisher: PHYSICS CURRICULUM+INSTRUCT.INC.
expand_more
expand_more
format_list_bulleted
Videos
Question
Chapter 7, Problem 22P
To determine
Calculate the work done by the force lifting the ladder.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
We can model a pine tree in the forest as having a compact canopy at the top of a relatively bare trunk. Wind blowing on the top of the tree exerts a horizontal force, and thus a torque that can topple the tree if there is no opposing torque. Suppose a tree’s canopy presents an area of 9.0 m2 to the wind centered at a height of 7.0 m above the ground. (These are reasonable values for forest trees.) If the wind blows at 6.5 m/s:
a. What is the magnitude of the drag force of the wind on the canopy? Assume a drag coefficient of 0.50.b. What torque does this force exert on the tree, measured about the point where the trunk meets the ground?
Problems 7.42 and 7.43
The driveway gate is hinged at its right end and can swing freely in the horizontal plane
The gate is pushed open by the force P that always acts perpendicular to the plane of the
gate at point A. which is a horizontal distance d from the gate hinge. The weight of the
gate is W = 215 lb, and its mass center is at G, which is a distance w/2 from each end
of the gate, where w = 16 ft. Assume that the gate is initially at rest, and model the gate
as a uniform thin bar as shown below the photo.
hinge line
/2
Problem 7.42i Given that a force of P
gate (i.e., d = w/2), determine the reactions at the hinge O after the force P has heen
continuously applied for 2 s.
20 lb is applied at the center of mass of the
Problem 7.43 Given that a
A 15,000 N crane can rotate around a frictionless shaft at its base and is supported by a cable that forms a 25-degree angle with the crane (see figure). The crane has16 m long and not uniform; its center of gravity is 7.0 m from the shaft measured along the crane. The cable is subject to 3.0 m from the top end of the crane. The crane rises to55o above the horizontal, holding a container with 11,000 N bricks by a very light rope of 2.2 m. Calculate a) the tension on the cable and b) the vertical and horizontal components of the force exerted by the shaft on the crane. Start by drawing a free body diagram of the crane.
Chapter 7 Solutions
Physics Fundamentals
Ch. 7 - Prob. 1QCh. 7 - Prob. 2QCh. 7 - Prob. 3QCh. 7 - Prob. 4QCh. 7 - Prob. 5QCh. 7 - Prob. 6QCh. 7 - Prob. 7QCh. 7 - Prob. 8QCh. 7 - Prob. 9QCh. 7 - Prob. 10Q
Ch. 7 - Prob. 11QCh. 7 - Prob. 12QCh. 7 - Prob. 13QCh. 7 - Prob. 14QCh. 7 - Prob. 15QCh. 7 - Prob. 16QCh. 7 - Prob. 1PCh. 7 - Prob. 2PCh. 7 - Prob. 3PCh. 7 - Prob. 4PCh. 7 - Prob. 5PCh. 7 - Prob. 6PCh. 7 - Prob. 7PCh. 7 - Prob. 8PCh. 7 - Prob. 9PCh. 7 - Prob. 10PCh. 7 - Prob. 11PCh. 7 - Prob. 12PCh. 7 - Prob. 13PCh. 7 - Prob. 14PCh. 7 - Prob. 15PCh. 7 - Prob. 16PCh. 7 - Prob. 17PCh. 7 - Prob. 18PCh. 7 - Prob. 19PCh. 7 - Prob. 20PCh. 7 - Prob. 21PCh. 7 - Prob. 22PCh. 7 - Prob. 23PCh. 7 - Prob. 24PCh. 7 - Prob. 25PCh. 7 - Prob. 26PCh. 7 - Prob. 27PCh. 7 - Prob. 28PCh. 7 - Prob. 29PCh. 7 - Prob. 30PCh. 7 - Prob. 31PCh. 7 - Prob. 32PCh. 7 - Prob. 33PCh. 7 - Prob. 34PCh. 7 - Prob. 35PCh. 7 - Prob. 36PCh. 7 - Prob. 37PCh. 7 - Prob. 38PCh. 7 - Prob. 39PCh. 7 - Prob. 40PCh. 7 - Prob. 41PCh. 7 - Prob. 42PCh. 7 - Prob. 43PCh. 7 - Prob. 44PCh. 7 - Prob. 45PCh. 7 - Prob. 46PCh. 7 - Prob. 47PCh. 7 - Prob. 48PCh. 7 - Prob. 49PCh. 7 - Prob. 50PCh. 7 - Prob. 51PCh. 7 - Prob. 52PCh. 7 - Prob. 53PCh. 7 - Prob. 54PCh. 7 - Prob. 55PCh. 7 - Prob. 56PCh. 7 - Prob. 57PCh. 7 - Prob. 58PCh. 7 - Prob. 59PCh. 7 - Prob. 60PCh. 7 - Prob. 61PCh. 7 - Prob. 62PCh. 7 - Prob. 63PCh. 7 - Prob. 64PCh. 7 - Prob. 65PCh. 7 - Prob. 66PCh. 7 - Prob. 67PCh. 7 - Prob. 68PCh. 7 - Prob. 69PCh. 7 - Prob. 70PCh. 7 - Prob. 71PCh. 7 - Prob. 72P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, physics and related others by exploring similar questions and additional content below.Similar questions
- A uniform ladder of mass 20 kg and length 13 m is resting, with its base on rough horizontal ground at a distance of 5 m from a rough vertical wall. The upper end of the ladder rests against the wall. The ground and the wall have the same coefficient of friction with the ladder. a. Show that if the ladder is stable, then the coefficient of friction satisfies the inequality μ> 0.2 [Sufficient working must be shown if full marks are to be awarded here.] b. If, in fact, μ= 0.36arrow_forwardA person opens a 7.25 kg door by applying a force of 12.5 N perpendicular to it at a point 0.85 m from the hinges. The door measures 2,25 m high and 1.15 m wide. Find the angular acceleration of the door. If the door is pushed wide open by 75,0° in 2.0 s, find the work done on the door and the power delivered to the door.arrow_forwardA device used for mixing consists of three identical thin rods extending from a central axle, all in the same plane, and spaced apart from each other by 120°. Each rod is 10.4 cm long, and attached to the end of each rod is a ball with a cross-sectional area 4.50 cm?. Each ball has a drag coefficient of 0.520. A motor drives the central axle, causing the device to rotate. (a) How much power (in W) must be supplied by the motor for the device to rotate at a constant speed of 1000 rev/min in air? (Use 1.20 kg/m3 for the density of air at 20°C.) (b) How much power (in W) must be supplied by the motor for the device to rotate at a constant speed of 1000 rev/min in water? (The density of water is 1.00 g/cm3, or 1,000 kg/m3.) warrow_forward
- A ladder whose length L is 12m and whose mass m is 45kg rests against a wall. Its upper end is a distance h of 9.3m above the ground. The center of gravity of the ladder is one-third of the way up the ladder. A firefighter whose mass M is 72kg climbs halfway up to the ladder. Assume that the wall, but not the ground is frictionless. What forces are exerted on the ladder by the wall and by the ground?arrow_forwardA tree contractor has been hired by a homeowner to remove a damaged tree from a previous storm. The top of the tree broke off, leaving the trunk in the ground. The arborist will remove the tree by attaching a rope near the top and cutting the base close to the ground. The scenario is shown in the figure. The distances in the figure are z=14.7 m,, h=1.45 m,, y=5.66 m and x=8.00 m. If the arborist pulls on the rope with a force of magnitude F=36.8 N,F=36.8 N, write the expression for the torque ττ with respect to the base P of the tree using ijkijk unit vector notation, →τ=τxi+τyj+τzk where τx,τy,and τz are the values of the torque components in the x-,, y-, and z-directions, respectively.arrow_forwardA 4.00 m length of lightweight cord is wound around a uniform cylindrical spool of radius 0.500 m and mass 1.28 kg. The spool is mounted on an axle with negligible friction and is initially at rest. The cord is pulled from the spool with a constant acceleration of magnitude 3.00 m/s2. (a)How much work has been done on the spool (in J) when it reaches an angular speed of 5.47 rad/s? (b)How long (in s) does it take the spool to reach this angular speed? (c)How much cord is left on the spool (in m) when it reaches this angular speed?arrow_forward
- A screwdriver turns a screw an angle of 5.85 radians by applying a torque given by (in Nm) 02 T=2.12 + 6. Calculate the work done, W by the torque. Enter W, measured in Joules, correct to three significant figures:arrow_forwardThe uniform thin pole has a weight of 30 lb and a length of 26 ft. If it is placed against the smooth wall and on the rough floor in the position d = 10 ft, will it remain in this position when it is released? The coefficient of static friction is us = 0.3. B 26 ftarrow_forwardA ladder with a length of 5.0 m and a weight of 650N is placed so its base is on the ground 4.0 m from a vertical frictionless wall, and its tip rests 3.0 m up the wall. The ladder remains in this position only because of the static friction force between the ladder and the ground. You, with a weight of 500 N, are standing on the ladder at a horizontal distance of 1.10 m from the wall. Assume the mass of the ladder is uniformly distributed. (a) Find the magnitude of the upward normal force applied by the ground on the ladder. (b) Find the magnitude of the horizontal normal force applied by the wall on the ladder. N (c) Determine the minimum possible coefficient of static friction for the ladder-ground interaction, for the ladder to remain at rest.arrow_forward
- A bar weighing 26.0 N is supported horizontally on each end by two hangingsprings, each 15.0 cm long, with spring constants 0.970 N/cm and 1.45 N/cm,respectively. The bar is 6.00 m long and has a center of mass 2.00 m from thespring with constant 0.970 N/cm. How far does each spring stretch?arrow_forwardA lever is used to lift a boulder. The fulcrum is placed 1.60 m away from the end at which you exert a downward force, producing a torque with a magnitude of 4.00 × 10^2 N • m. If the angle between the force and the lever is 80.0°, what is the magnitude of the applied force? Assume that the lever is massless.arrow_forwardA 40-kg door with a height of 2.0 m and a width of 0.80 m is hinged at the end of the door along its vertical height. What is the kinetic energy of the door if it swings at 6.3 rad/s about a vertical axis that passes through the hinge of the door?arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice University
University Physics Volume 1
Physics
ISBN:9781938168277
Author:William Moebs, Samuel J. Ling, Jeff Sanny
Publisher:OpenStax - Rice University
Work-Energy Theorem | Physics Animation; Author: EarthPen;https://www.youtube.com/watch?v=GSTW7Mlaoas;License: Standard YouTube License, CC-BY