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Questions tagged [friction]

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

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Does the angular momentum of the cornering/turning car change the travel direction of the wheels of the car?

I think this is purely a physics question and does not require any deep knowledge of vehicle dynamics. The cornering car has angular momentum with a rotation around a vertical axis but when you ...
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Force and friction [on hold]

A plank of mass $10\ kg$ and a block of mass $2\ kg$ are placed on a horizontal plane one above other (block above plank). There is no friction between plane and plank. The coefficient of friction ...
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1answer
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Force required to move bar at one end

A uniform bar of length $L$ and weight $W$ rests on a level floor so that there is a uniform contact pressure between floor and bar. A horizontal force $P$ is applied at one end, normal to the bar. If ...
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Calculating torque required to rotate a platform [on hold]

I am trying to spec out a motor's torque required to rotate a platform about an axis. The attached diagram makes it better to understand. Dimensions are in cm: I have an arbitrary shaped object on ...
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calculate the work done on a 1500-kg elevator car by its cable to lift it 40.0 metres at a constant speed, assuming friction averages 100N [on hold]

choose the correct answer and show all working. 5.92 x 10^5 J 5.92 x 10^2 J 5.92 x 10^4 J 5.12 x 10^5 J (in my opinion, the correct answer is 5.92 x 10^4 J but I am not sure).
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The minimum force required to move the block is [on hold]

My question : A block of mass 4 kg is placed to a rough vertical wall with a normal force of 100N.The coefficient of static and kinetic friction are 0.5 and 0.3 respectively. The minimum force ...
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40 views

Newtons second law appliance [on hold]

Assume we have one box, and we put another box on it. A box of $m_1=4\ \rm{kg}$ and a box of $m_2=2\ \rm{kg}$. The box with more mass ($m_1$) is in the bottom. What will happen if we apply a force of ...
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Newton's Third Law bulldozer and pulley system [on hold]

A 3.74×104 kg bulldozer pushes a 9.35×103 kg boulder. If the wheels of the bulldozer push against the ground with 66800 N of force, what is the magnitude of the force between the boulder and the ...
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Why does a gyroscope increases its velocity when it has a frictional force related to it? [on hold]

When a gyroscope is precessing in a certain angle different than the parallel with the weight of the gyroscope, the velocity of the body increases. Why does it happen?
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Elementary physics question related to banking on roads

I am studying 12th grade physics. I encountered this concept while studying circular motion and frictional force. You can find the relevant equations here Friction on roads While practicing the ...
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1answer
61 views

Is friction affected by gravity?

Some people said that moving a car on the moon would make the tires spin a bit more compared to Earth's. But then I started thinking that if static friction and gravity are perpendicular to each other,...
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Mechanics and Newton's laws of physics [closed]

A scissor is used to cut a wire of circular cross section and negligible weight the wire slides in the direction away from the hinge until the angle between the scissor blades become 2 alpha. Find the ...
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1answer
53 views

Why doesn’t a ball “roll” straight down the wall?

I conducted a physics experiment today. I simply held up a small ball against the wall, and let go. I was expecting the ball to exhibit some rolling motion of some sort due to friction, but to my ...
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0answers
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Sliding between three blocks kept on a smooth surface? [closed]

Here is how I tried to solve In the answer the mass of (md) is 3m but I am getting m. I have a conceptual mistake I am not getting it . Please help .
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1answer
37 views

The path of a disk/cylinder with translation and rotation [closed]

The conditions: We have a regular disc of mass $\mathrm{M}$ and radius $\mathrm{R}$. It is placed on a horizontal plane with friction (which is constant throughout). It is then given an initial ...
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1answer
90 views

Motorcycle wall of death: what diameter should the enclosure be so that the cyclists can travel at maximum speed? [closed]

You are asked to build a country fair version of an old classic motocycle stunt in which the riders start inside a circular enclosure with vertical walls about 4.90 meters high. Around the top of this ...
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3answers
69 views

Why do lighter pendulums come to rest faster than heavier ones?

I've been reading this website, which stated: All pendulums eventually come to rest with the lighter ones coming to rest faster. I have been taught the mass of a pendulum does not affect its ...
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1answer
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Why does water hold up between the teeth of my comb?

Image for reference: As can be seen in the above image, whenever my comb comes in contact with water, a little of it is trapped between the teeth. This happens whether I dip it in still water or ...
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2answers
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Why do we assume the coefficient of static friction is maximum in problems involved with rolling objects on inclined planes?

The maximum force of static friction between two surfaces is roughly proportional to the magnitude of the normal force $N$ pressing the two surfaces together. In many problems involving rolling ...
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4answers
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Why is $mg = bv$ and not $mg = -bv$?

I was given two formulas, $$F_D = -bv $$ $$F_D = -bv^2 $$ and was told that at terminal velocity, $$v = \frac{mg}{b} $$ which implies that $$mg = bv$$ $$mg + (-bv)=0$$ $$mg + F_D = 0$$ From ...
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1answer
73 views

$μ = \tan\theta$ - Why? It makes sense mathematically, but if it's based on the materials how does that work?

We were presented with a problem in physics today in which we calculated that the coefficient of static friction is equal to the tangent of an angle This is on a ramp using the laws of friction. My ...
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What are the equations of friction in a pulley?

This is for an industrial pulley. It have an axis, a rotative part and two sides. Everything is in steel except that there is a bronze plain bearing tied to the rotative part. So that friction is ...
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1answer
125 views

Friction between two blocks on top of each other

I am a little bit confused to the concept of friction between two blocks on top of each other. there could be two situations: the first situation is when all surfaces are frictionless including that ...
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2answers
45 views

Special cases in friction [closed]

Imagine that 2 objects are stacked. The friction between the objects is higher than the friction between the bottom object and the ground. Is it possible for the top object to be pushed hard enough to ...
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1answer
50 views

Finding out heat generated in presence of variable force when minimum work done [closed]

Ques: A portion of a floor in a lab is made friction less.A homogeneous bar of length l= 1.0m placed on the friction less portion perpendicular its boundary is being dragged by pulling it with the ...
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2answers
35 views

Dynamics of a sphere in a horizontal plane driven by a force

I'm studying the dynamics of a sphere in a horizontal plane driven by a force. The situation is the following: I have a stationary sphere of mass $m$ and radius $r$ in a pool table whose lining has ...
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1answer
22 views

Dynamic friction

In my house, we are debating whether when you scrub the floor it is easier or more difficult to drag a piece of furniture. My floor is made of marble, who's right?
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2answers
25 views

Displacement using work energy principle

How do you use the work energy principle to find the displacement of an object. With of course the mass, speed and friction forces given?
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1answer
34 views

rolling friction of a solid sphere

This may be a very rudimentary question. I have two spheres on a physics simulator and I need to define various parameters including rolling friction, spinning friction, inertia, color etc. I was ...
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0answers
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Can a car accelerate on a frictionless surface? [duplicate]

i have string of related questions. i know that the internal forces cannot result in acceleration of a body and so in daily life, car engine applies force to rotate wheels that produce friction force (...
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3answers
111 views

How long does a coin take to slide off a turntable?

So I was helping my daughter prepare for a AP physics test. I studied Physics at university many many years ago and always assume I'll be able to figure out any reasonable question about mechanics. I ...
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1answer
47 views

Maxwell's wheel and friction

We experimented with the Maxwell's wheel today and at the end we were asked about why does this apparatus stop since there is conservation of energy. I did some research and apparently there is a type ...
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2answers
57 views

Work done by friction on a body which is rolling on an inclined plane [closed]

Why is the work done by friction zero during translational motion but nonzero when the body is rolling on an inclined plane?
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3answers
103 views

Basic question on friction

Consider the whole system initially at rest.Suppose there is friction between the blocks, but not between the lower block and the floor. Suppose I apply a Force F to the left over M, with F greater ...
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1answer
34 views

Damped oscillations and generalized friction

I'm reading damped oscillations from the book Classical Mechanics by Landau and Lifshitz, quoting from the text - "There exists, however a class of problems where motion in medium can be ...
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0answers
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How friction works? [duplicate]

I learned that friction comes from the tiny crashes between the small bumps of uneven surface of each object. And I could make a rough guess about why heat is produced when two objects are rubbed ...
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1answer
43 views

How does one mathematically derive the damping coefficient of a theoretical viscous dashpot?

I am very well aware of how to get the damping coefficient experimentally by observing a system in action. Given the dimensions and fluid properties of a theoretical viscous fluid dashpot, how does ...
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1answer
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Dependency of kinetic friction [duplicate]

1.Why kinetic friction doesn't depend on speed of object? Also explain why static friction > kinetic friction > rolling friction? 2.when we keep a book on a table , the table is said to exert a ...
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3answers
28 views

Rolling friction and motion [duplicate]

The frictional force in a motion of a rolling body is along the direction of motion. Then what stops the motion of a rolling body?
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1answer
60 views

Finding the frictional coefficient

This is going to be very long question. A 1 kg block situated on a rough incline is connected to a spring constant 100Nm as shown in fig. The block is released from rest with the spring in the ...
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0answers
18 views

Principle of least action for dissipative systems [duplicate]

I am trying to solve a problem with involves friction, and am having trouble solving it with $F=ma$. I am considering to use Lagrangian mechanics, but I am puzzled. There doesn't seem to be a ...
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0answers
22 views

Why can we use conservation of energy even when friction is involved? [duplicate]

A solid cylinder of mass $m$ and radius $r$ starts rolling down an inclined plane of inclination $\theta$. Friction is enough to prevent slipping. Find the speed of center of mass when its center of ...
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2answers
79 views

When you have engine at idle and turn your car, where does the kinetic energy go?

When you turn the front wheels to the right for example, your car will tend to continue in its original forward direction. However, there is friction between the wheel and the ground that prevents it ...
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1answer
38 views

How far does a teflon ball roll on a very even surface? [closed]

As teflon has a minimal frictional coefficient of about 0.04, how far does a ball made of teflon roll on a even surface in comparison to another ball (made of wood or iron, for example), when pushed ...
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1answer
21 views

Damping in a stick-slip model

Usually the spring/block stick-slip models also include a damper. eg: https://nptel.ac.in/courses/112102015/10 I don't really understand the purpose of the damper. What does it represent? Also, ...
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2answers
75 views

why is friction acting towards the centre in a level curved road? [duplicate]

We all know that friction is a force that opposes motion and is applied in the opposite direction of motion, but in a leveled curved road it becomes the centripetal force and pulls towards the center. ...
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2answers
32 views

Weight distribution's effect on riding uphill

Two different chains of cars (attached to each in a row) are driving uphill (Only the first car is motorized): The first chain consists of 3 cars, each 4000 kg. The second chain consists of 3 cars, ...
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3answers
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How can an engine provide more torque at the point of contact than the ground's response by static friction without slipping?

In response to the top answer here: Newtonian Mechanics - How does something like a car wheel roll? I clearly fundamentally misunderstand something here. I can't reconcile there being an angular ...
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2answers
89 views

What is the force that actually propels a human forward in a train or car?

This question arises after much debate with some fellow engineering students and we are looking for somewhat of a theoretical answer more than anything. When you are sitting in a train or a car, what ...
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2answers
50 views

Car Motion using Tire Friction

I am a bit confused regarding how car moves. Following is the explanation which I've come up with after reading but I would like if someone verifies and corrects it. If a car is moving, the ...