(a) A father pulls his child on a sled by pulling on a rope which is 30° with the horizontal, over his shoulder with a force of 50 N. Using the coefficient of friction for steel on ice, calculate the acceleration of the sled if its mass plus the child's is 20 kg, assuming that the sled is already in motion. (b) What minimum force must the father exert to start the sled moving from rest? µy = 0.02, Hs = 0.4

(a) A father pulls his child on a sled by pulling on a rope which is 30° with the horizontal, over his shoulder with a force of 50 N. Using the coefficient of friction for steel on ice, calculate the acceleration of the sled if its mass plus the child's is 20 kg, assuming that the sled is already in motion. (b) What minimum force must the father exert to start the sled moving from rest? µy = 0.02, Hs = 0.4

International Edition---engineering Mechanics: Statics, 4th Edition

4th Edition

ISBN:9781305501607

Author:Andrew Pytel And Jaan Kiusalaas

Publisher:Andrew Pytel And Jaan Kiusalaas

Chapter7: Dry Friction

Section: Chapter Questions

Problem 7.78P: The figure shows a steel bar being processed by a rolling mill. Given that P=80kN and r =0.016,...

See similar textbooks

Similar questions

A block weighing 2.50 kg begins its motion from a stationary position at point A, located at the highest point of a frictionless ramp. The ramp is inclined at an angle of 40° relative to the horizontal and has a length of 1.50 m. As the block slides down the ramp, it reaches a region between point B and point C, which is a rough horizontal surface with a kinetic friction coefficient of 0.30. After covering a distance of 1.00 m on the horizontal surface, the block encounters a lightweight spring with a spring constant of 900 N/m. A. Find the total energy for point A and point B? B. Find the speed of the block at point B? C. What is the cumulative work performed on the block as it moves along the rough horizontal surface? D. By employing the work-energy theorem, determine the velocity of the block at point C just before it collides with the spring?
To climb a 400 meter high mountain, you have two options, a straight line route with a 40 ° slope or a route composed of 5 equal sections (same length) each with a 20 ° slope. If traveling in a car with a mass of 1280 kg and a maximum power of 88 kW, Determine (assume the whole car as a particle): a) Is the friction enough to prevent the car from sliding? The coefficient of static friction of the tires with the ground is 0.95. b) What is the power required to climb the 40 ° slope at a constant speed of 40 km / h? Does the car have enough power to go up at that speed? c) What is the constant speed at which the 40 ° slope can be climbed with a 60 kW power? d) What is the power required to climb a 20 ° slope at 40 km/h? Does the car has enough power to go up at that speed? e) In which of the two trajectories does the car do more work? Ignore the resistance of the air and rolling resistance and radius of curves between sections of the compound route. Please add the free body diagram.
A force of 150 N pushes a 100 N block up an incline whose slope is 3 vertical to 4 horizontal. If the coefficient of kinetic friction is 0.12, determine the time required, in seconds, to increase the velocity of the block from 3 to 15 m/sec. The force is applied parallel to the incline.
consider the mass and pulley system in the attached file. mass m1 = 29 kg and mass m2 = 12kg. the angle of the inclined plane is given and the coefficient of kinetic friction between mass m2 and the inclined plane is uk = 0.12. assume the pulleys are massless and frictionless when mass m2 moves a distance 4.94 m up the ramp, how far downward does mass m1 move? d= ?
1) Jonny pulls his sister Jane (weight 28 lbs), who is sitting in a wagon, up an incline ramp (θ = 17°) with a steady speed. If the coefficient of kinetic friction is 0.18, the wagon has a mass of 14 kg, and the length of the ramp is 2.4 m, find: the work done by the frictional force. the work done by the gravitational force.
Please answer this NEATLY, COMPLETELY, and CORRECTLY for an UPVOTE. Block D, initially at rest, having a W = 30 lbf , is supported within the system shown, with x = 13.2 ft. Neglecting the mass of the pulley and the cord on the system, determine the eventual height h after a force P = 60 lbf is applied to make the block rise by ∆sD = 0.625 ft at t = 2.5 s. NOTE: Use Force-Mass-Acceleration (FMA) Method.
A 25-kg block is initially at rest on a horizontal surface, and a horizontal force of 75.0 N is required to set the block in motion after which a horizontal force of 60.0 N is required to keep the block moving with constant speed. Find (a) the coefficient of static friction and (b) the coefficient of kinetic friction between the block and the surface.
A 1.21 kilogram block is released from rest on a 13.33° frictionless incline. The object proceeds down the incline to the horizontal surface where it slides 4.34 m before it stops. The height of the incline is 3.53 m. what is the coefficient of kinetic friction on the horizontal surface?
Fred pushes a 55 kg refrigerator with a force P = 100 N inclined at 30° from the horizontal at 1.60 m from the floor as shown in the diagram. The coefficient of static friction between the floor and the refrigerator is 0.40.1. Which among the choices shows the limiting value of the frictional force between the refrigerator and the floor?A) 90.9 NB) 195.8 NC) 108.8 ND) 490 N2. Is the refrigerator not moving, moving, or on the verge of moving? Prove this through calculations.3) Write the correct moment equilibrium equation about A for the refrigerator. (Just use P, don't use P =100)
Consider the system shown below. The incline plane is fixed and the coefficient kinetic friction between M and 2M is ?1, and coefficient kinetic friction between the plane and 2M is ?2. Let M=2.0kg, ?=22o, ?1=0.14, and ?2=0.25. (a) What is the magnitude of the frictional force on mass M? (b) What is the magnitude of the total frictional force on mass 2M? (c) What is the acceleration of mass M? (d) What is the acceleration of mass 2M?
A block of mass m1 = 20Kg is attached by an ideal pulley to a block of mass m2 = 2.5 kg on the surface of a table, between the surface of the table and the block m1 there is a friction coefficient of 0.4. The system starts from rest when both masses have moved 0.75m. Calculate: A) The total work of the system. B) The speed of the system when it has traveled the 0.75m. C) The total work of the M1 mass. D) The speed of the m1 mass when it has traveled the distance of 0.75m. E) The speed of the mass m2 when it has traveled the distance of 0.75 m
A slowly moving conveyor belt passes through a small opening in a wall which is high enough to accommodate a single package, but a reckless worker stacks two packages on the belt. The one at the bottom, package 1 which has mass m1m1, continues, without slipping against the belt, through the opening. (The belt continues without slowing.) The one on the the top, package 2 with mass m2m2, presses firmly against the wall and slips across the lower package. The same coefficients of friction, μsμs and μkμk, apply between the pair of packages and between the package and the belt. Weights, if required, will be denoted with the corresponding subscript of the package as F⃗ g,iF→g,i, for i=1,2i=1,2. The normal force exerted by object aa on object bb, if required, will be denoted as F⃗ n,a→bF→n,a→b for a,b∈{1,2,belt,wall}a,b∈{1,2,belt,wall}, but a≠ba≠b. The force of kinetic friction exerted by object aa on object bb, if required, will be denoted as F⃗ k,a→bF→k,a→b for…