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

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0answers
26 views

Free body driagram of box and plate with a friction force on a smooth surface

On a smooth surface we have a plate of 40 kg and on that plate a a box of 10 kg. Between the plate and the box there is a ...
2
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2answers
36 views

Work done by frictional force on a sliding block

A block slides across a table horizontally with an initial velocity $V$. The frictional force $F$ brings it to rest after its Centre of Mass covers distance $S$. What is the work done by the ...
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1answer
76 views

When will the pringles can fall?

When I'm pushing a tall, cylindrical object stood on its end (like a Pringles can) I can push it near its bottom, and it will slide forwards, or push it near the top, and it will topple over. So, ...
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2answers
33 views

How does friction product heat?

Suppose there are two similar particle-like objects attempting to "bump" against each other to create friction, they are prevented from colliding against one another due to either electrostatic ...
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0answers
40 views

Simple question. Where to find coefficients of friction? [on hold]

I am trying to calculate the force the Terracotta Warriors apply to the Lykan Hypersport in the Fast and Furious 7 movie. I am trying to find the frictional force of the statues applied against the ...
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1answer
174 views

Sliding ruler on table top

I've got a standard foot-long flat plastic ruler (about an inch wide) and a desk with a smooth formica-like surface. When idly passing time reading on the computer, I will pick up one side of the ...
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2answers
2k views

Water pressure calculation for a volume of water at a given height

I'm looking to create a rain harvesting system. I have a 275 gallon IBC tote that is 48" x 40" x 46". I have an adapter for a 3/4 garden hose at the bottom of the IBC tote. I'm trying to figure out ...
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2answers
54 views

Why doesn't a magnet on a refrigerator slide down?

Obviously gravity pulls objects towards the earth's surface. Now suppose I have a refrigerator and a magnet. The magnetic force is perpendicular to the gravitational force. So it is not counteracting ...
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1answer
32 views

Speed, weight and force [on hold]

If a road roller of weight $W$ is rolling on the road at the speed of $X\,\mathrm{kmph}$, how much force does it apply on the surface of the road (considering a sampled surface of the same size as ...
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1answer
26 views

Frictional force [closed]

a box of banana weighing 40N rests on a horizontal surface. the coefficient of static friction between the box and the surface is 0.4 and coefficient of kinetic friction is 0.2. a. if no horizontal ...
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0answers
28 views

Exam preperation [closed]

I really need your help preparing for my upcoming exam. here are my questions:
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2answers
32 views

What theories or formulas are involved with velocity

What theories or formulas are involved or can be added as background information in an experiment that sees a small toy car roll freely down an incline where the surface area is altered to cause more ...
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3answers
52 views

why does a ball roll

I searched for my question and I found many results but all of them eventually try to solve something specific (like solving for the kinetic energy or finding when does the ball stop). what I want ...
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3answers
7k views

Does a car use friction to move?

When a car's engine injects fuel into the cylinder chambers, the reaction creates a force that generates rotational momentum to the shaft and over the transmission, it translates that power to the ...
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1answer
33 views

What causes angular and linear deceleration in a sliding and rotating ring?

I was solving an AP Physics problem involving a ring sliding and rotating over a frictional surface. When I started to think about why the ring eventually comes to a stop I started to become confused. ...
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2answers
38 views

Period of a simple pendulum accounting for friction

The period of a simple pendulum is $$T=2\pi\sqrt{\ell/g},$$ but no where in there do I see that it accounts for friction. Does it somehow account for friction, and if not, how could you do that?
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1answer
149 views

Heuristic equation for Friction force between materials

I'm programming a game where different types of objects will be sliding over different types of terrains (Top-down in two dimensions). At my current level of physics education we are given the ...
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3answers
945 views

Will a violin string keep vibrating for a longer time in vacuum than in air?

Hitting a string of a violin or a guitar will cause that string to vibrate, but after short time the amplitude of the vibration will decay, consequently the produced sound will die out. I suppose ...
2
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5answers
194 views

How can static friction do work?

By definition, the work done by a force is $W = F\cdot d$, so how can static friction do work? Can this force move the body a distance of $75~\text{m}$?
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1answer
25 views

The applied and friction forces of a particle along a straight wire in horizontal plane

A particle of mass $14~\text{kg}$, slides along a straight wire in a horizontal plane. The coefficient of dynamic friction $\mu_k = 0.6$ The equation of the line of the wire is $y = \sqrt{3}x$ so ...
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2answers
141 views

Is work done in rolling friction?

I am confused by rolling friction. Suppose you have a cylinder rolling which starts at rest at the top of an incline plane and begins to roll down the plane without slipping. Is work done by the ...
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2answers
104 views

Friction force in rolling motion

In rolling without slipping motion we know that the friction acting is static friction and so we treat it as an unknown while solving equations of dynamics. Question: Is the static friction during ...
0
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1answer
54 views

Work done by friction on car

David Morin, in "Introduction to Classical Mechanics" says that friction does not exert a force on a car because the ground is fixed but that KE of the car is changing to internal kinetic energy in ...
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1answer
25 views

Frequency response of a capstan-like mechanical amplifier

Tension on a wire can be amplified by wrapping the wire around a powered rotating capstan, with output force governed by the linear capstan equation, Tout = Tin * emu*theta. Will this equation hold ...
3
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1answer
224 views

Rolling a ball into a cone; what should the forces overall be?

This is my solution to finding angular displacement/velocity/acceleration on cone so far. Consider a cone, with an apex of half-angle $\psi$ pointing down, and a height of $h$. If I roll a ball into ...
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2answers
314 views

Conservation of Angular Momentum and linear velocity

I have a problem where a cylinder is moving on a horizontal surface, starting with velocity $v_0$. It is given that its radius is $10\text{cm}$, its mass is $200\text g$ and the coefficient of ...
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0answers
37 views

Is it possible to formulate a Hamiltonian for a damped system?

I recently found out that it is possible to formulate a Hamiltonian for a system with time-dependent coordinates such that the Hamiltonian is not the same as the energy When is the Hamiltonian of a ...
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4answers
3k views

Static Friction - Only thing that can accelerate a train?

I'm a computer programmer that never studied physics in school and now it's coming back to bite me a bit in some of the stuff I'm being asked to program. I'm trying to self study some physics and ...
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4answers
1k views

Would a three wheeled vehicle be faster than a four wheeled vehicle of the same weight?

If I have a four wheeled vehicle (small wooden block with metal nail axles and plastic wheels) and apply a force X to it, would it be made faster by keeping one wheel off the ground in order to reduce ...
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3answers
449 views

Direction of friction force between two boxes

There are two boxes on top of each other. The bottom box is dragged right by a constant force. What is the direction of friction of the top box against the bottom box?
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3answers
200 views

Why are some surfaces slippery?

Why are ice and oil slippery? In general, why do certain substances make a surface difficult to walk on?
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1answer
231 views

How to get rotational speed after disk-disk collision with friction?

Assume two circular disks A and B collide. They have both initial linear momentum and angular momentum. If their surface has no friction, their angular velocity does not change after collision, so I ...
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2answers
4k views

Is water considered a substance with low friction or high friction?

Like, for example, rubber is a substance with high friction, as an object with neither high or low friction would easily stop on it, and wouldn't skid. Ice is considered an object with low friction, ...
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1answer
31 views

Finding the acceleration of a mass/pulley system without knowing the direction of the displacement

I have the following question: I noticed that if I solve for the acceleration assuming that the acceleration is occuring to the left, I get the equation: $\displaystyle a = ...
3
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1answer
76 views

Is it possible to eliminate Van der Waals interactions?

I came to know that the friction force actually depends on the surface contact area due to weak interactions (adhesion due to Van der Waals forces) between the atoms of both materials increasing in ...
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1answer
40 views

Can Tension between two blocks on a horizontal plane be discovered in these conditions? [closed]

the bodies are linked by an ideal string, one has m1=10kg & the other m2=20kg The force is known and is pulling horizontally, F=60N on the lighter object the coefficient of friction is said to be the ...
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1answer
274 views

Block Sliding Down a Plane (Perpendicular Velocity)

I'm having trouble understand the concepts for this problem. Here's the problem: A block is placed on a plane inclined at angle $\theta$. The coefficient of friction between the block and the ...
3
votes
3answers
400 views

Would this box on the floor rotate based on friction?

There is a floor that friction is proportional to its velocity (like $F=-kv$) and there is a box with its width as $l$ and its height as $h$. (you may assume that $l$ is longer than $h$). It is on the ...
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1answer
80 views

Inclined plane, circular motion and the friction

Suppose we have a cylinder on an inclined plane of mass $m$ and radius $R$ moving without sliding (so that $\varepsilon = a/R$). Why is the friction $F$ causing the circular motion sometimes lower ...
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2answers
1k views

Different directions of frictional force when objects are rolling

My textbook has two instances of rolling bodies (smooth rolling). In the first, the body is rolling on the horizontal floor with some acceleration of its centre of mass. In this case, the book says ...
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1answer
34 views

Equilibrium when it shouldn't be?

I'm doing an experiment that requires me to balance a ring, tied to four strings, in the middle of a force table; in other words, the objective is to set the ring at equilibrium. Each string is ...
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4answers
68 views

How can a petrol car require less fuel at 55mph than a lower speed at the same rpm?

It seems to be widely accepted that somewhere around 55mph is the most economical speed to drive in a conventional petrol car. Recently I ordered an EV, and learned that (with the exception of at ...
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2answers
50 views

Force needed to hold a book between your hands - not sure about the influence of friction

I'm looking at this problem: A student presses a book between his hands, as the drawing indicates. The forces that he exerts on the front and back covers of the book are perpendicular to the ...
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3answers
70 views

Maximum acceleration for a vehicle [closed]

I'm in engineering school and we have a project: we have to build a amphibioues vehicle; I'm looking for a formula. Our vehicle has to go as far as possible with its unique source of energy, a ...
20
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5answers
3k views

Does a car consume more fuel when it's raining?

Yesterday my wife asked me that question, and I couldn't answer. Consider a car, in a sunny day, and that is consumes x gallons per mile. Considering that everything is equal, except that it's ...
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1answer
43 views

Role of roughness in friction

In many textbooks static and kinetic friction is explained by surface roughness and interlocking asperities. However this website: http://amasci.com/miscon/miscon4.html#fric which is cited in ...
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2answers
72 views

Question about circular motion of car turning

When we move round a roundabout there is a frictional force between the tires and the road that acts towards the centre of the roundabout in order to produce the circular motion. Why then do we ...
2
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1answer
63 views

Rolling w/o slipping - does a friction force acts in this scenario?

Assume the following scenario of rolling without slipping: A small disk starts rolling w/o slipping at $\vec{r}_{CM}=-9R\hat{x}$ (scenario A) and reaches the bottom of the large hollow disk ...
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2answers
26 views

Can there be friction unless the objects in contact are not acted upon by an external force?

The definition of friction I read from The book, General Physics written by Henry Crew is that, The resistance which either one of the body offers to the motion is called force of friction". If it is ...
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2answers
151 views

Physical interpretation of initial conditions for damped mass-spring system

I have background in pure mathematics so my question is about physical meaning. If we consider equation for damped mass-spring system, it is linear ordinary second order differential equation. So to ...