A worker slowly moves a 50-kg crate to the left along a loading dock by applying a
Question:
(a) The coefficient of kinetic friction between the crate and the loading dock,
(b) The corresponding magnitude P of the force.
1.2 m 15° 0.9 m lc
Step by Step Answer:
Free body Crate Threeforce body Reaction E must pass through K where P ...View the full answer
Vector Mechanics for Engineers Statics and Dynamics
ISBN: 978-0073398242
11th edition
Authors: Ferdinand Beer, E. Russell Johnston Jr., David Mazurek, Phillip Cornwell, Brian Self
Related Video
Static friction and kinetic friction are two types of friction that occur when two objects are in contact with each other. Static friction is the force that must be overcome to initiate motion between two surfaces that are in contact with each other but are not moving relative to each other. It is caused by the interlocking of rough surfaces at the microscopic level, and it increases as the force pushing the surfaces together increases. Once motion between the surfaces starts, the static friction is no longer present. Kinetic friction, also known as sliding friction, is the force that opposes the motion of two surfaces that are in contact with each other and are moving relative to each other. It is caused by the rubbing of the surfaces against each other and the resistance of the molecules in the surfaces to being moved. Kinetic friction is generally less than static friction, but it can still be a significant force, especially at high speeds. Both static and kinetic friction can be quantified using a coefficient of friction, which is a dimensionless number that represents the ratio of the frictional force between two surfaces to the normal force (the force perpendicular to the surfaces). The coefficient of static friction is typically greater than the coefficient of kinetic friction for a given pair of surfaces, because it takes more force to overcome the interlocking of the surfaces at rest than to maintain motion once it has started.
Students also viewed these Mechanics questions
-
The crate has a weight W1 and a center of gravity at G. If the coefficient of static friction between the crate and the floor is s, determine if the man of weight W2 can push the crate to the left....
-
To pull a 50 kg crate across a horizontal frictionless floor, a worker applies a force of 210 N, directed 20o above the horizontal. As the crate moves 3.0 m, what work is done on the crate by (a) The...
-
To push a 25.0 kg crate up a frictionless incline, angled at 25.0o to the horizontal, a worker exerts a force of 209 N parallel to the incline. As the crate slides 1.50 m, how much work is done on...
-
Determine the reactions at the beam supports for the given loading when wO = 400 lb/ft. 300 lb/ft A. 5 ft
-
The following accounts appear in the ledger of Sather Inc. after the books are closed at December 31, 2012. Common Stock (no-par, $1 stated value, 400,000 shares authorized, 250,000 shares issued)...
-
A real estate agent is interested in the relationship between the number of lines in a newspaper advertisement for an apartment and the volume of inquiries from potential renters. Let volume of...
-
The Honeybee dataset contains data collected from the USDA on the estimated number of honeybee colonies (in thousands) for the years 1995 through 2012. We use technology to find that a regression...
-
The Hydro-Electric Company (HEC) has three sources of power. A small amount of hydroelectric power is generated by damming wild and scenic rivers: a second source of power comes from burning coal,...
-
HTBM Ltd. has an outstanding issue of bond with a par value of $1,000, paying 8 percent coupon rate semi-annually. And, the company just paid a dividend of $2.70 per share. The dividends are expected...
-
The Harvey City Comprehensive Case consists of the last problem in each chapter from Chapters 4 through 15. Completing this case essentially requires that you account for all the transactions of a...
-
A uniform crate with a mass of 30 kg must be moved up along the 15° incline without tipping. Knowing that force P is horizontal, determine (a) The largest allowable coefficient of static friction...
-
A half-section of pipe weighing 200 lb is pulled by a cable as shown. The coefficient of static friction between the pipe and the floor is 0.40. If = 30, determine (a) The tension T required to move...
-
What factors explain why some researchers conclude that labor market discrimination against women is small while others come to a different conclusion? [Hint: you may also want to consult the inset...
-
Explain why tension (in ropes, etc.) and the contact forces between surfaces are not fundamental forces.
-
Startups do well in crowded industries under two conditions: (1) they create meaningful value for customers at a fair price and (2) they differentiate themselves from competitors in ways that create...
-
A 1-kg cart and a 2-kg cart are held together with a coupler that contains a small charge. The charge is exploded and sends the \(1-\mathrm{kg}\) cart rolling away at \(+4.0 \mathrm{~m} /...
-
A bullet of speed \(v\) and inertia \(m\) strikes and gets embedded in a wooden block of inertia \(M\), initially at rest on a low-friction floor. Plot \(k_{f} / k_{i}\) as a function of \(M / m\)...
-
A 60-g Mars bar will supply you with \(1095 \mathrm{~kJ}\) of energy. How many of them would you need to get enough energy to climb the first \(800 \mathrm{~m}\) of the highest structure in the...
-
The following display is a graph similar to one that appeared in USA TODAY (June 29, 2009). This graph is meant to be a bar graph of responses to the question shown in the graph. a. Is response to...
-
Calculate the electrical conductivity of a fiber-reinforced polyethylene part that is reinforced with 20 vol % of continuous, aligned nickel fibers.
-
Rod AB can slide freely along the floor and the inclined plane. At the instant shown the angular velocity of the rod is 4.2 rad/s counterclockwise. Determine (a) The velocity of end A of the rod, (b)...
-
The disk shown moves in the xy plane. Knowing that (vA)y = ?? 7 m/s, (vB)x = ??7.4m/s, and (vC)x = ??1.4 m/s, determine (a) The angular velocity of the disk, (b) The velocity of point B. A 600 mm
-
In Prob. 15.41, determine (a) The velocity of point O, (b) The point of the disk with zero velocity. 14hPa) + 1" (Pay=Px 600 mm A $1(a)=1
-
f(x)=5x-3, g(x)=x-5 (f+g)(x)=(Simplify your answer.)
-
(5) A small maintenance project consists of the following jobs whose precedence relationships are given below: Job 1-2 1-3 2-3 2-5 3-4 Immediate Predecessor 15 15 3 5 8 8 Activity 3-6 4-5 4-6 5-6 6-7...
-
Let X be a binomial random variable with the probability distribution f(x) shown below. Find the probability distribution of the random variable Y=x. f(x)= Bere 3-x x=0,1,2,3 elsewhere Complete the...
Study smarter with the SolutionInn App