ODI48. (II) A small box is held in place against a rough verticalwall by someone pushing on it with a force directed upwardat 28° above the horizontal. The coefficients of static andkinetic friction between the box and wall are 0.40 and0.30, respectively. The box slides down unless the appliedforce has magnitude 23 N. What is the mass of the box?49. (II) Two crates, of mass 65 kg and 125 kg, are in contact andat rest on a horizontal surface (Fig. 4-57). A 650-N forceis exerted on the 65-kg crate. If the coefficient of kineticfriction is 0.18, calculate (a) the acceleration of the sys-tem, and (b) the force that each crate exerts on the other.(c) Repeat with the crates reversed.650 N65 kg 125 kgFIGURE 4-57Problem 49.50. (II) A person pushes a 14.0-kg lawn mower at constantspeed with a force of F = 88.0 N directed along the handle,which is at an angle of 45.0° to the horizontal (Fig. 4-58).the bedof abou56. (II) Aerates cimpedifriction57. (II) ThmFIGURE 4-5Problems 5758. (II) A bplane shgo? (b)

Answered: Image /qna-images/answer/fc15b72e-0ea2-45b4-9d37-a6e762e942a7.jpg

(II) A small box is held in place against a rough vertical wall by someone pushing on it with a force directed upward at 28° above the horizontal. The coefficients of static and kinetic friction between the box and wall are 0.40 and 0.30, respectively. The box slides down unless the applied force has magnitude 23 N. What is the mass of the box?

(II) A small box is held in place against a rough vertical wall by someone pushing on it with a force directed upward at 28° above the horizontal. The coefficients of static and kinetic friction between the box and wall are 0.40 and 0.30, respectively. The box slides down unless the applied force has magnitude 23 N. What is the mass of the box?

Principles of Physics: A Calculus-Based Text

5th Edition

ISBN:9781133104261

Author:Raymond A. Serway, John W. Jewett

Publisher:Raymond A. Serway, John W. Jewett

Chapter5: More Applications Of Newton’s Laws

Section5.1: Forces Of Friction

Problem 5.3QQ: You are playing with your daughter in the snow. She sits on a sled and asks you to slide her across...

See similar textbooks

Similar questions

In a television commercial, a small, spherical bead of mass 4.00 g is released from rest at t=0in a bottle of liquid shampoo. The terminal speed is observed to be 2.00 cm/s. Find (a) the value of the constant bin the equation v=mgb(1ebt/m), and (b) the value of the resistive force when the bead reaches terminal speed.
Show that the acceleration of any object down an incline where friction behaves simply (that is, where fk=kN ) is a=g(sinkcos). Note that the acceleration is independent of mass and reduces to the expression found in the previous problem when friction becomes negligibly small (k=0).
You are playing with your daughter in the snow. She sits on a sled and asks you to slide her across a flat, horizontal field. You have a choice of (a) pushing her from behind, by applying a force downward on her shoulders at 30 below the horizontal (Fig. 5.2a) or (b) attaching a rope to the front of the sled and pulling with a force at 30 above the horizontal (Fig 5.2b). Which would be easier for you and why?
A freight train has a mass of 1.5x 10^7kg. If the locomotive can exert a constant pull of 7.5x 10^5N how long doesit take to increase the speed of the train from rest to 80 km/h?
A bird has a mass of 2.4 kg lands on the middle horizontal telephone wire, and depresses the wire such that it makes an angle of 25.0 degrees with the horizontal. Find the Tension in the wire.
The 1.5-Mg four-wheel-drive Jeep is used to push two identical crates, each having a mass of 500 kg. If the coefficient of static friction between the tired and the gournd is us=0,6 , determine the maximum possible speed the Jeep can achieve on 5 s without causing the tired to slip. The coefficient of kinetic friction between the crates and the ground is UK=0.3
Does it need a static friction force? Is it at rest?
If the coefficient of kinetic friction between a 22-kgcrate and the floor is 0.30, what horizontal force is requiredto move the crate at a steady speed across the floor? Whathorizontal force is required if is zero?
A 10.0 kg mass rests on an incline that is 30.0 m long and 15.0 m high. The coefficient of friction between the mass and incline is 0.400. If the mass is allowed to slide down the incline, its acceleration will be what?
A mobile is formed by supporting four metal butterflies of equal mass m from a stringof length L. The points of support are evenly spaced a distance ℓ apart as shown inFigure P5.54. The string forms an angle θ1 with the ceiling at each endpoint. Thecenter section of string is horizontal. (a) Find the tension in each section of string interms of θ1, m, and g. (b) In terms of θ1, find the angle θ2that the sections of stringbetween the outside butterflies and the inside butterflies form with the horizontal. (c)Show that the distance D between the endpoints of the string isFigure P5.54
(I) Suppose you are standing on a train accelerating at 0.20 g. What minimum coefficient of static friction must exist between your feet and the floor if you are not to slide?
In the design of a supermarket, there are to be several rampsconnecting different parts of the store. Customers will haveto push grocery carts up the ramps and it is desirable thatthis not be too difficult. The engineer has done a survey andfound that almost no one complains if the force requiredis no more than 18 N. Ignoring friction, at what maximumangle θ should the ramps be built, assuming a full 25-kg cart?