Questions tagged [friction]

The resistance a surface or object encounters when moving over another.

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0answers
33 views

Factors effecting the time period of Euler's disk [closed]

I wish to carry out research on the factors effecting the time period of a spinning Euler's disk. Do factors like friction coefficient of the base or concavity of the base effect the disk? If not, ...
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Turbulent flow in a pipe - how to compute the friction coefficient $\lambda$

Consider a pipe of diameter $D = 0.01$ m and Length $L = 1.0$ m represented in the figure underneath. At the in- and outlet, the pipe cross-section converges, respectively diverges smoothly. We will ...
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48 views

What are the forces acting on this car?

i found a cool website that explains sort of like the forces acting on the car and they seem to explain the process behind it. the website gives a free body diagram but the problem is that it doesn't ...
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How does different shuffleboard powder affect the disks' speed

I do know there is friction and surface tension involved here but am not sure on how exactly does different kinds of shuffleboard powder affect the disks' speed. So taking into the account the ...
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4answers
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Understanding the notion of lose or win of angular momentum in accretion disk

Here is below a slide of one of my lecture in planetology : I understand well the fact that ring A will be slow down by friction with ring B since ring B is rotating slower and the inverse process (...
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Explaining friction using Hamiltonian mechanics

I have heard the opinion that it is a good assumption that microscopically all forces are actually conservative so in principle all classical mechanics problems could be solved using Lagrangian / ...
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935 views

Why we can't write in air? [closed]

Why we always require a surface to write something? Why we can't write in air? I think that it is due to friction but I am not sure about it. Edit As per helpful comments and responses, I think ...
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1answer
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Is there a reference frame in which the static friction from rolling does positive work?

I am worried this will be deleted as a duplicate question, so I will try to be extra clear what I am asking: In some reference frames, static friction can do positive work. If you have a crate in the ...
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Force to start moving a car

I have 2 related questions, the second one is more engineering than physics, but it relies on the first. Does it take more force to get a car to start moving than to accelerate it the same amount ...
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1answer
66 views

Are there any formulas that calculate the stopping distance of a car on different surfaces that include deceleration?

I already found the formula $d = v^2/2\mu g$ where '$v$' is for velocity, '$\mu$' is for the coefficient of friction between the tires and the road surface, and '$g$' is the acceleration of gravity. ...
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Why does friction occur? [duplicate]

I'm pretty sure this is a rather stupid question but I just cannot wrap my mind around the reasoning behind friction. Now, an obvious explanation would be that since all surfaces are inherently rough,...
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62 views

how does a car move? and how do the brakes affect its velocity? [duplicate]

im doing a project that requires me to understand how cars move. from what I understand , its the friction that is creates in the tires that enables the tire to rotate, which then push the car forward....
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51 views

A circular motion problem [closed]

A car goes on a horizontal circular road of radius $R$, the speed increasing at a constant rate $\frac{dv}{dt}=a(constant)$. The friction coefficient of the tyre is $\mu$. Find the speed at which the ...
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3answers
76 views

Is friction enabling relative motion between bodies in contact?

If the surface object B is placed on is frictionless, on applying a force F on object A, friction will act on object A opposite to the direction of the force applied (opposite to the direction of its ...
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56 views

Explain why the magnets move towards eachother in this setup

I have two bar magnets (actually stacks of small magnets, but I believe they should behave the same) attached to a stack of (presumably conductive) coins, and not diametrically opposite. When I ...
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34 views

Centripetal Force Static Friction

I understand that when a car is turning, it is using static friction to do so. The wheel is turned where the perpendicular component of the wheel is opposing the direction of motion, creating a force ...
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At what speed in air would a solid object turn to plasma?

Just curious, friction can heat up what ever is moving. The faster something moves the quicker it heats up. Is it possible in the perfect scenario to turn a speeding solid object to plasma through ...
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How to calculate the viscous damping coefficient of a viscous layer between an inner sphere and an enclosing outer sphere?

In this article by Rahn and Barba, a flat-spin transition manoeuvre is investigated. For this it is assumed that a rigid spacecraft contains a spherical, dissipative fuel slug of inertia $\boldsymbol{...
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1answer
36 views

Force Required To Move A Wheel

Consider a wheel upright like this: Is the force required to move the wheel by pushing it in the direction that its tire is facing the same magnitude as the force required to move it by pushing at ...
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2answers
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Free body diagram for a non-fixed (movable) ramp, with a box at rest on top of it

I'm having trouble figuring out how this free body diagram would look. The question involves a block at rest on a ramp, which is in turn at rest on a table. All objects are made of the same material, ...
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3answers
78 views

Normal reactions with moments

A uniform ladder, $AB$, is leaning against a smooth vertical wall on rough horizontal ground at an angle of $70°$ to the horizontal. The ladder has length $8\ \rm m$, and is held in equilibrium by a ...
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3answers
41 views

Friction on car tires

In tipler and mosca 5th edition the following passage occurs: I am a bit confused by the sentence starting "If the power delivered by the engine is small enough...". I am not seeing why the power ...
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1answer
54 views

Billiard ball with side spin

A cue ball is travelling along a snooker table. Initially, it has only side spin (yaw). As it travels it will develop a rolling spin (pitch). Can the ball develop any (roll) and thus move off the ...
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How to calculate coefficient of friction of given surface?

I have a surface in real life whose coefficient of kinetic friction I need to calculate. I've seen a method where people attempt to measure the angle at which the object on top begins to slide off the ...
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1answer
28 views

Static equilibrium (possibility)

In static equilibrium for a ladder leaning against the wall it is supposed to rotate about a point. Why we are not assuming it to slide down as in our practical life?
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1answer
51 views

Sign of the work done by dissipation forces

I don't understand this passage from the book I'm reading: Physically, it is clear that a system cannot be conservative if friction or other dissipation forces are present, because $\mathbf{F}\...
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Does Horizontal Velocity remain constant when it hits a surface in a Parabolic Motion?

It is told in one of the answers that the horizontal velocity stays at 4.0 m/s after the ball bounces from the plate. Why is it still at 4.0m/s, isn't there friction or is it neglected for the sake ...
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Calculating the Slip Ratio of a Vehicle Tire

I am trying to create a simulation to simulate a vehicle's tire using Pacejka's Magic Formula. From what I understand, the formula calculates the longitudinal force that the tire will experience using ...
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1answer
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Finding the accelerations of objects [closed]

I want to know how to get the accelerations separately in each object
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Work done by frictional force when rolling without slipping [duplicate]

When an object is rolling (no slipping) on a slope there should be a frictional force which causes rotation. But when we use power insulation philosophy, we haven't considered about an energy loss ...
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1answer
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Incline plane question with both static and kinetic friction [closed]

A box of mass m = 2.5 kg is released from rest near the top of the incline. The angle of the incline is 35 degrees above the horizontal. The coefficients of static and kinetic friction between the box ...
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1answer
39 views

No friction in pure rolling - how about driving a car?

I remember the un-intuitive result that pure rolling without acceleration involves no friction by the law of conservation of angular momentum. Conjectures: I understand that when I'm driving a car at ...
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4answers
107 views

Principle of friction force

When two equal and opposite forces act on a body at rest or in motion we say it is rest or in its state of motion. But when a body kept on a table starts moving uniformly due to a force applied, it ...
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2answers
65 views

What force is acting on a car?

We say acceleration is produced in a body when a force acts on it in some direction.When a car moves with acceleration and I'm an observer on ground.What force should I say is acting on the car?
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Why the capstan equation is exponential? [closed]

Does anybody knows any intuitive explanation about the reason that the capstan equation is exponential and not, as expected, linear?
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1answer
65 views

Does a velocity perpendicular to the gravitational force affect frictional force? [closed]

A motorcycle rides on the vertical walls around the perimeter of a large circular room. The friction coefficient between the motorcycle tires and the walls is μ. How does the minimum μ needed to ...
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16 views

What is the internal force at the end of a tire and relation to the torque?

If an car axle is subject to a torque and if I consider the contact point of the tyre to the ground, it is stationary. Assume the car is moving left to right. Would the contact point be subject to an ...
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3answers
139 views

Why do office chairs rotate when pushed/pulled out?

A common source of frustration when I'm at work is the fact that my rolling office chair's wheels rotate whenever I push it forward or backward from my desk, which can cause it to bump my computer ...
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2answers
107 views

what are the sources of energy loss for a ball rolling down slope?

I am experimenting in lab with an iron sphere rolling down a smooth aluminum ramp. The final velocity is smaller than the one predicted assuming energy conservation (see calculations below), which ...
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2answers
56 views

Why is the work done by friction zero when body is rolling? [duplicate]

Why is the work done by friction zero when body is rolling? Does it mean no energy is dissipated by friction.
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3answers
59 views

Is vector sum of momentum constant if there is friction?

In a head-on collision of 2 objects with the same mass and speed in opposite directions, the vector sum of momenta before and after the collision stays the same and is equal to zero. I've read that if ...
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2answers
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Real Pulley and Newton's Third Law

In a real pulley with two masses hanging from either side, the pulley rotates due to a non-zero torque, which I understand is caused by friction on the rope. I understand that if each mass was ...
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3answers
128 views

Why does friction not accelerate a wheel?

It seems like a silly question because this defies common sense, but it appears that friction is supposed to accelerate a wheel (not attached to anything). We can derive from Newton's laws that $\...
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1answer
35 views

maximal acceleration of a wheel-driven vehicle

I was thinking about the maximal acceleration of a bicycle, I found a similar question. What remains unclear is that I found two coefficients of friction, one for rolling and one for static friction. ...
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2answers
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Will a wheel keep rolling in perfect vacuum? [duplicate]

I have a query which I cannot resolve by finding enough arguments. A perfectly round wheel that also doesn't have any contractions due to gravity is placed in a perfect vacuum, so no drag is present. ...
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4answers
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Work when there is more than 1 force

I know that for an object with an applied force, the work done is $$W = Fd \cos \theta.$$ I was wondering what would happen when there is another force (e.g. friction)? Is it better to say that the ...
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2answers
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Why does less friction in a wheel result in more speed? [duplicate]

Everyone knows that racing bikes have narrower wheels and that, by definition, friction reduces speed. What I don't understand is that since at no time is the wheel of the bike in horizontal motion ...
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4answers
79 views

Car flip in crash while dragging

In some movies (Cars2), a driver would take a sharp turn while dragging the car and it would launch in air and flip. Can this happen in real life? If yes then what is the physics behind it? Only ...
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How can friction do no work in case of pure rolling?

I have read various answers , on PSE and elsewhere , and most of them explain that the point of contact of the rolling object undergoes 0 instantaneous displacement in the direction of friction, I ...
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Do you have an idea for two easy experiments to measure the coefficients of static and sliding friction of a rope wrapped around a steel rod?

I'm researching a phenomenon dependent on the Capstan/Euler-Eytelwein-Equation. To model a simulation, I need the friction coefficients. I came up with the idea of hanging one mass $m_1$ on one side ...