The resistance a surface or object encounters when moving over another.
1
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0answers
47 views
Is there any place you can safely skydive without a parachute?
While trying to explain to someone how a kitten walked away from a fall from a skyscraper I got to wondering if there's any place a human could do that and I find myself out of my depth.
The only ...
3
votes
2answers
54 views
Does the slip-stick phenomenon have any application?
The slip-stick phenomenon is present all around us, be it the noise of car breaks or in earthquakes. But does it have any real-life application?
0
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1answer
160 views
Deceleration of Vehicle off pavement
How would I calculate the deceleration of a vehicle (ATV), wheels locked, on dirt? How long would it take to halt? How fast is it decelerating?
I used this calculator, but it seems incorrect for a ...
1
vote
1answer
62 views
Friction on a conveyor belt
I was surfing through an Olympiad paper and I was caught with this question.
A block of mass 1 kg is stationary with respect to a conveyor belt that is accelerating with $1\, \tfrac{m}{s^2}$ ...
1
vote
1answer
79 views
Coefficients of friction for steel, aluminum & polymers
I am trying to analyse the problem of sticking an aluminum piece to a stainless steel piece only with pressure. The holding capacity of the system is determined by the static friction between the two ...
0
votes
0answers
19 views
newton's laws - involving block and conveyor belt [closed]
i was surfing through a physics book when i encountered this problem-
A block of mass 1 kg is stationary with respect to a conveyor belt that is accelerating
with 1 m/s^2 upwards at an angle of ...
-1
votes
1answer
53 views
Comparing Static Frictions
In this figure, which of the static frictional forces will be more?
My aim isn't to solve this particular problem but to learn how is static friction distributed . Since each of the rough-surfaces ...
0
votes
1answer
60 views
Work done by Static friction
Here $v1$ is relative to the block on which sphere is pure rolling but static friction isn't $0$ as of now .
In the following diagram, is work done by static friction $0$ ?, since the point of ...
2
votes
1answer
113 views
Angular momentum conservation while internal frictional torque is present
So this appears in a problem which looks simple enough in its context; It's something like this:
Two discs, A and B, are mounted coaxially on a vertical axle. The discs have moments of inertia $I$ ...
2
votes
1answer
82 views
Approximating Rolling/Sliding in 2D Shape
I'm trying to find more information on how a 2D shape (could be defined by a function, such as ellipse, or by a polygon) will roll across a surface. The shape could be nearly circular or quite ...
0
votes
0answers
50 views
Work And Energy Question [closed]
$H = 3\text{ m}$,$m=2\text{ kg}$
The right side is rough.
I want to figure:
what is the coefficient of friction $\mu$?
How high and exceed the maximum return on the plane right body?
I know ...
4
votes
3answers
2k views
Why are bicycle pedal threads' handedness left on the left and right on the right?
I understand the reason that bicycle pedals are oppositely threaded on either side. What I don't understand is why it works because I'm missing something.
Take the right pedal for example. It's ...
3
votes
1answer
76 views
Angular momentum after elastic collision
If two balls collide (elastically) and there is no friction between them, will their angular momentum change after the collision?
1
vote
2answers
174 views
Preventing a block from sliding on a plane (with friction)
Assume a small square block $m$ is sitting on a larger wedge-shaped block of mass $M$ at an upper angle $\theta$ such that the little block will slide on the big block if both are started from rest ...
0
votes
2answers
130 views
Why is simple harmonic motion called so?
Is the motion of a simple pendulum, a simple harmonic motion? It stops vibrating after sometime.
4
votes
1answer
55 views
Are there real life applications for Hausdorff dimensions, specifically crack formations?
I was curios about Hausdorff dimensions. They seem to neatly describe rough surfaces. So I was wondering if there are common applications of Hausdorff dimensions in things like complicated friction ...
2
votes
1answer
267 views
How does the resistance force on a rolling ball depend on the ball radius?
A billiard ball set gently rolling on a billiard table slows and stops, because it is decelerated by resistance forces at the contact between the ball and table.
I expect the magnitude of the ...
6
votes
0answers
113 views
What determines the angle of the cushion on a pool table?
If you look at the cushions (bumpers) on a pool table, you'll see that they're not vertical. They're tilted inwards. About 10 years ago, I came across a physics exam in which one of the problems ...
1
vote
1answer
34 views
What is $\gamma$ in the damping equation?
$x''+\gamma x'+w_0^2x=0$
That is the general equation for damped harmonic motion. What is the term or name that describes $\gamma$?
Is it called the damping constant? I know its the ration between ...
5
votes
1answer
454 views
Dependence of Friction on Area
Is friction really independent of area? The friction force, $f_s = \mu_s N$. The equation says that friction only depends on the normal force, which is $ N = W = mg$, and nature of sliding surface, ...
1
vote
0answers
34 views
Does friction depend on the area between bodies thats in contact? [duplicate]
Does friction depend on the area between bodies thats in contact? If yes why we make threads on vehicles tires and below shoes? Does it not cause reduce in friction?
4
votes
2answers
94 views
Why is the damping force on a spring oscillator linearly dependent on velocity?
If you consider the damping force is friction like in:
then the force should be $$F=\mu N$$ where $\mu$ is the coefficient of kinetic friction. Why then is the damping force assumed to be linearly ...
0
votes
3answers
74 views
Smallest force to move a brick
Having a brick lying on a table, I can exert horizontal force equal to $\mu m g$ to a middle of it's side, and it will start moving (assume $\mu$ is the friction coefficient). However, can I make the ...
-2
votes
0answers
68 views
Man ,Pulley, block system? [closed]
In the figure $m_{A}=m_{B}=m_{C}=60 kg$. The coefficient of friction between $C$ and ground is $0.5$, $B$ and ground is $0.3$, $A$ and $B$ is $0.4$. $C$ is pulling the string with the maximum possible ...
2
votes
1answer
124 views
Two masses attached to a spring
I'm trying to understand the solution of the following problem.
Two masses $m_{1}$ and $m_{2}$ slide freely in a horizontal frictionless track and are connected by a spring whose force constant is ...
3
votes
2answers
530 views
Is the wind's force on a stationary object proportional to $v^2$?
I am on a boat docked at Cape Charles, VA, about 30 or 40 miles from the center of Hurricane Irene. This understandably got me thinking about the force of wind on the boat. Since air friction is ...
3
votes
7answers
1k views
Simple friction formula for a car
I am making a 2D driving video game, and I would like to know the "simple" formula for calculating the friction force between the car and the road. I have read lots of friction diagrams involving ...
3
votes
2answers
85 views
Orbit in the vacuum
As the space is a vacuum and there is no friction in space,
Can we assume that, if we place an object in gravity in exactly the right distance from a planet with gravity and in the right acceleration, ...
3
votes
3answers
65 views
Friction on roads
I have a question with which I am having trouble.
A 71m radius curve is banked for a design speed of 91km/h. Given a coefficient of static friction of 0.32, what is the range of speeds in which a car ...
2
votes
4answers
610 views
Why does a tire produce more traction when sliding slightly?
It is well known in racing that driving the car on the ideal "slip angle" of the tire where it is crabbing slightly from the pointed direction produces more cornering speed than a lower slip angle or ...
2
votes
0answers
92 views
Why did increasing the Ackermann geometry in my race car make it faster in corners?
Ackermann geometry is used to account for the different radius arcs that the front tires follow when the steering wheel is turned from center. It's often expressed as a percentage: e.g. 25% Ackermann, ...
25
votes
6answers
1k views
Can I survive a free fall using a ramp and a rope?
Can I survive a free fall by carrying a very light and resistant ramp using a rope?
Note: lets assume the ramp is a little bit heavier at the bottom and I am very skilled at making it always land ...
0
votes
1answer
60 views
How to find work done due to friction [closed]
The force F=40N is applied on a 10kg block at an angle of 36 with the horizontal. The block moves a distance of 15m. If the surface is frictionless. If the coefficient of kinetic friction is 0.25, ...
1
vote
1answer
82 views
calculating work done by friction
I want to calculate the work done by friction if the length $L$ of uniform rope on the table slides off. There is friction between the cord and the table with coefficient of kinetic friction $\mu_k$.
...
0
votes
1answer
109 views
Determining the frequency of a ruler laying on two spinning cylinders [closed]
I am stuck on this homework problem. Any help would be appreciated, even if it's a push in the right direction.
A ruler of mass m = 75g and L = 3.0 meters is placed so that it is exactly balanced ...
0
votes
1answer
50 views
Hyperbolic, parabolic, elliptical PDE related to under-, critical- and overdamped in harmonic osciallation
A damped harmonic oscillator has three cases for the damping: underdamped, critically damped and overdamped. With partial differential equations, I know the hyperbolic wave equation, the parabolic ...
0
votes
1answer
2k views
How to calculate work done by variable kinetic friction force?
A heavy chain with a mass per unit length $\rho$ is pulled by the constant force $F$ along a horizontal surface consisting of a smooth section and a rough section. The chain is initially at rest on ...
3
votes
1answer
88 views
Calculating the path of a ball with spin moving across a table
A ping pong ball is rolling over a smooth (but not frictionless) table. During its travel, a clockwise spin is placed on the ball. The ball's path is changed to move to the right (in perspective from ...
1
vote
1answer
111 views
Work done by friction
Suppose we have a block of mass $M$ and we are moving it up a curve, very slowly ($a=0$). The surface is not smooth, and coefficient of friction is $\mu=\mu_s=\mu_k$.
To move the block we apply a ...
1
vote
2answers
164 views
Projectile Motion with Drag
The overall goal is to write a Mathematica program that will compute the launch angle that will yield the greatest range with using [RandomInt] function, but I was having trouble with the physics.
In ...
0
votes
1answer
117 views
A very elementary question regarding force of friction
When I first studied friction I faced f = $\mu$ N where f is force of friction, $\mu$ is coefficient of friction for the surface considered and N is the normal force for the body on surface. Now f is ...
4
votes
3answers
794 views
Block on a block problem, with friction
Consider two blocks, one on top of the other on a frictionless table, with masses $m_1$ and $m_2$ respectively. There is appreciable friction between the blocks, with coefficients $\mu_s$ and $\mu_k$ ...
2
votes
2answers
136 views
How can a train locomotive generate enough traction to pull all the coaches?
Sorry for posting what may be an obvious question but we just learning about friction at school and my teacher couldn't explain well enough to me and I would appreciate your inputs.
Consider the ...
0
votes
0answers
56 views
Work done by friction (homework) [closed]
A 40 kg case is pushed across a floor at a steady speed of 1.5 m/s. When the pushing stops, the case slides a further distance of 1.2m before coming to rest. Calculate the frictional force acting on ...
0
votes
1answer
417 views
Finding the force of friction of a moving object and its change when it accelerates to a constant speed
I have been searching for a straight forward answer to this question for ages now and it is driving me crazy.
Here is what I know:
If an object is moving at a constant speed the force of friction ...
2
votes
1answer
115 views
Skiing downhill
The other day on skiing holiday we've been arguing about whether an adult has weight advantage over a child when skiing downhill.
I was claiming that gravity is a constant regardless of object's ...
2
votes
2answers
247 views
Does a ski racer with a larger mass have an advantage?
Does a ski racer with a greater mass have an advantage over a racer with a lesser mass?
If mass of one racer is 54 kg and the mass of a more slender racer is 44 kg I know the speed at which they ...
1
vote
1answer
37 views
friction on atomic scale
I am getting into friction on an atomic scale. For instance, take two rigid layers of atoms of the kind A that are placed on top of each other, just like putting two boards of wood on top of each ...
0
votes
0answers
46 views
Work, energy and friction [closed]
A car loaded with bricks has a total mass of 18kg and is pulled at a constant speed by a rope. the rope is inclined 30 degrees with above the horizontal, and the cart moves 20.0 m on a horizontal ...
3
votes
2answers
233 views
Will two trains running along the equator in opposite direction experience same wear out?
Two identical trains, at the equator start travelling round the world in opposite directions. They start together, run at the same speed and are on different tracks. Which train will wear out its ...
