/designe mal forces on each other, as well as frictional forces that resist their slipping relative to contact forces arise from a complex interplay between the electrostatic forces between lons in the objects and the laws of quantum mechanics. As two surfaces are pushed ces increase exponentially over an atomic distance scale, easily becoming strong the buik material in the objects ifthey approach too close. In everyday experience, limited by the deformation or acceleration of the objects, rather than by the atomic forces. Hence, we can conclude the following contact forces is determined by EF = mä, that is, by the other forces on, and e contacting bodies. The only exception is that the trictional forces cannot exceed jun n be smaler than this or even zero) and f paralel to the plane of contact. Kinetic friction when surfaces slide When one surface is siding past the other experiments show three things about the friction force (denoted f a 1. The frictional force opposes the relative motion at the point of contact. 2 f is proportional to the nomal force, and 3. the ratio of the magnitude of the frictional force to that of the normal force is fairty constant over a wide range of speeds The constant of proportionality is called the coefficient of kinetic triction, often designated a As long as the sliding continues, the frictional force is then = Pan (valid when the surfaces side by each other). Static friction when surfaces don't slide When there is no relative motion of the surfaces, the trictional force can assume any value from zero up to a maximum n where is the coeficient of static triction. Invariably. is larger than a in agreen is large enough that something breaks loose and starts to slide, it offen accelerates. The frictional force for surfaces with no relative motion is therefore f
/designe mal forces on each other, as well as frictional forces that resist their slipping relative to contact forces arise from a complex interplay between the electrostatic forces between lons in the objects and the laws of quantum mechanics. As two surfaces are pushed ces increase exponentially over an atomic distance scale, easily becoming strong the buik material in the objects ifthey approach too close. In everyday experience, limited by the deformation or acceleration of the objects, rather than by the atomic forces. Hence, we can conclude the following contact forces is determined by EF = mä, that is, by the other forces on, and e contacting bodies. The only exception is that the trictional forces cannot exceed jun n be smaler than this or even zero) and f paralel to the plane of contact. Kinetic friction when surfaces slide When one surface is siding past the other experiments show three things about the friction force (denoted f a 1. The frictional force opposes the relative motion at the point of contact. 2 f is proportional to the nomal force, and 3. the ratio of the magnitude of the frictional force to that of the normal force is fairty constant over a wide range of speeds The constant of proportionality is called the coefficient of kinetic triction, often designated a As long as the sliding continues, the frictional force is then = Pan (valid when the surfaces side by each other). Static friction when surfaces don't slide When there is no relative motion of the surfaces, the trictional force can assume any value from zero up to a maximum n where is the coeficient of static triction. Invariably. is larger than a in agreen is large enough that something breaks loose and starts to slide, it offen accelerates. The frictional force for surfaces with no relative motion is therefore f
College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
Related questions
Question
![**Contact Forces Introduced**
**Learning Goal:**
To introduce contact forces (normal and friction forces) and to understand that, except for friction forces under certain circumstances, these forces must be determined from net force, \( \Sigma \mathbf{F} = m \mathbf{a} \).
Two solid objects cannot occupy the same space at the same time. Indeed, when two objects touch, they exert repulsive normal forces on each other, as well as frictional forces that resist their slipping relative to each other. These contact forces arise from a complex interplay between the electromagnetic forces between the electrons and ions in the atoms of the objects’ surfaces. Because the surfaces are pushed together, these forces increase exponentially over a uniform distance scale. It’s easy by becoming strong enough to distort the bulk material in the objects if they approach too close. In everyday experience, contact forces are intimately linked to motion or acceleration of the objects, rather than by the fundamental interatomic forces. Hence, we can conclude the following:
The magnitude of contact forces is determined by \( \Sigma \mathbf{F} = m \mathbf{a} \), that is, by the other forces on, and acceleration of the contacting bodies. The only exception is that the frictional forces cannot exceed \( \mu m \) (although they can be smaller than this or even zero).
### Normal and Friction Forces
Two types of contact forces operate in typical mechanics problems, the normal and frictional forces, usually designated by \( n \) and \( f \) (or \( F_{\text{fric}} \), or something similar) respectively. These are the components of the overall contact force; \( n \) perpendicular to and \( f \) parallel to the plane of contact.
**Kinetic friction when surfaces slide**
When one surface is sliding past the other, experiments show three things about the friction force (denoted \( f_k \)):
1. The frictional force opposes the relative motion at the point of contact.
2. \( f_k \) is proportional to the normal force, and
3. the ratio of the magnitude of the frictional force to that of the normal force is fairly constant over a wide range of speeds.
The constant of proportionality is called the coefficient of kinetic friction, often designated \( \mu_k \). As long as the sliding continues, the frictional force is then
\[ f_k = \mu_k n \] (valid when the surfaces](/v2/_next/image?url=https%3A%2F%2Fcontent.bartleby.com%2Fqna-images%2Fquestion%2F5e343f85-ac09-4dac-ae1f-fa90b444949b%2F1a166da5-a5ab-4781-b8b7-45b3ca55fdba%2F5g0kdyo_processed.png&w=3840&q=75)
Transcribed Image Text:**Contact Forces Introduced**
**Learning Goal:**
To introduce contact forces (normal and friction forces) and to understand that, except for friction forces under certain circumstances, these forces must be determined from net force, \( \Sigma \mathbf{F} = m \mathbf{a} \).
Two solid objects cannot occupy the same space at the same time. Indeed, when two objects touch, they exert repulsive normal forces on each other, as well as frictional forces that resist their slipping relative to each other. These contact forces arise from a complex interplay between the electromagnetic forces between the electrons and ions in the atoms of the objects’ surfaces. Because the surfaces are pushed together, these forces increase exponentially over a uniform distance scale. It’s easy by becoming strong enough to distort the bulk material in the objects if they approach too close. In everyday experience, contact forces are intimately linked to motion or acceleration of the objects, rather than by the fundamental interatomic forces. Hence, we can conclude the following:
The magnitude of contact forces is determined by \( \Sigma \mathbf{F} = m \mathbf{a} \), that is, by the other forces on, and acceleration of the contacting bodies. The only exception is that the frictional forces cannot exceed \( \mu m \) (although they can be smaller than this or even zero).
### Normal and Friction Forces
Two types of contact forces operate in typical mechanics problems, the normal and frictional forces, usually designated by \( n \) and \( f \) (or \( F_{\text{fric}} \), or something similar) respectively. These are the components of the overall contact force; \( n \) perpendicular to and \( f \) parallel to the plane of contact.
**Kinetic friction when surfaces slide**
When one surface is sliding past the other, experiments show three things about the friction force (denoted \( f_k \)):
1. The frictional force opposes the relative motion at the point of contact.
2. \( f_k \) is proportional to the normal force, and
3. the ratio of the magnitude of the frictional force to that of the normal force is fairly constant over a wide range of speeds.
The constant of proportionality is called the coefficient of kinetic friction, often designated \( \mu_k \). As long as the sliding continues, the frictional force is then
\[ f_k = \mu_k n \] (valid when the surfaces
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
This is a popular solution!
Trending now
This is a popular solution!
Step by step
Solved in 2 steps
Recommended textbooks for you
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON