A weight of 10 N resting on an inclined plane at 30° to the horizontal is connected by a string passing over a frictionless pulley at the upper end of the inclined plane. The free end of the string is connected to a weight of 20 N which hangs in air. If the coefficient of friction of the inclined surface is 0.2, calculate the time taken by the hanging weight to decend by 1 m. (1) ON H=0.2 (2) 30° 20N Given diagram Fig s=1m

A weight of 10 N resting on an inclined plane at 30° to the horizontal is connected by a string passing over a frictionless pulley at the upper end of the inclined plane. The free end of the string is connected to a weight of 20 N which hangs in air. If the coefficient of friction of the inclined surface is 0.2, calculate the time taken by the hanging weight to decend by 1 m. (1) ON H=0.2 (2) 30° 20N Given diagram Fig s=1m

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 7.81P: Calculate the horizontal force P required to push the 85-lb lawn mower at constant speed. The center...

See similar textbooks

Similar questions

Calculate the horizontal force P required to push the 85-lb lawn mower at constant speed. The center of gravity of the mower is at G, and the coefficients of rolling resistance are 0.12 for the front wheels and 0.18 for the rear wheels.
Two identical chairs, each weighing 14 lb, are stacked as shown. The center of gravity of each chair is denoted by G. The coefficient of static friction is 0.2 at B (the contact point between the chairs) and 0.35 at A, C, and D. Determine the smallest force P that would cause sliding.
A wedge is used to prop up the 6000-lb block of marble. The wedge angle is =30, and the angle of static friction is s=12 between all contact surfaces. Determine the smallest force P that would prevent the wedge from sliding out.
Draw the FBD of the entire frame, assuming that friction and the weights of the members are negligible. How many unknowns appear on this FBD?
The figure shows a steel bar being processed by a rolling mill. Given that P=80kN and r =0.016, determine the force F required to advance the bar at a constant speed.
The coeffient of static friction between the uniform bar AB of weight W and the ground is 0.45. Find the smallest angle and the corresponding force P that would initiate simultaneous tipping and sliding of the bar.
Repeat Prob. 4.152 assuming that the 400-kN force is applied at O instead of L.
The block of weight W is pulled by the force P inclined at the angle to the horizontal. Find the smallest force P and the corresponding angle that would cause impending sliding of the block. The angle of static friction between the block and the ground is s.
A rigid gate of a flood control structure in a river is 6 m wide by 4 m high and weighs 10 kN. With its longer edge horizontal, it is moved up and down with its short edges sliding in vertical channel guides. Evaluate the force, in kN, needed to raise the gate when the surface of the water is 2 m. above its top edge. There is no water on thedownstream side of the gate. The coefficient of friction between the gate and the channel guides is 0.10. Neglect the buoyant effect of the water on the gate and the weight of the cables connected to the gate.a. 104 b. 94 c. 110 d. 92
PROBLEM: To prevent a box from sliding down an inclined plane, student A pushes on the box in the direction parallel to the incline, just hard enough to hold the box stationary. In an identical situation, student B pushes on the box horizontally. If the weight of the box w= 20.0 N, the angle made by the incline with the horizontal θ=25o, and the coefficient of static friction µs=0.16, who has the easier job?
A 150 lb man can climb up15 ft on a 20 ft ladder before it slips. What must the coefficient of friction be if the ladder is arranged so that its base makes an angle of 50 ̊ with the ground? Assume the ladder to be uniform and weighing 100 lb.
Box A weighs 1000N and has a height of H1=3m and width W1=2m. Box B weighs 800N. the static friction coefficient between the boxes is uA=0.7 and the static friction coefficient between box B and the ramp is uB=0.5. Find the max allowable angle for the following instances where no motion occurs, box A and B remain stationary. 1) Box A slides, Box B remains stationary 2) Box A tips, Box B remains stationary 3) Box B slides, Box A remains stationary on block B