Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [friction]

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

0
votes
1answer
23 views

Effect of air resistance of the period of a pendulum [duplicate]

Does air resistance increase or decrease the period of a simple pendulum?
1
vote
1answer
21 views

Calculate the kinetic friction velocity vector from the kinetic friction force in a simulation

I am doing (programming) a simple kinematic 2D simulation on blocks. The idea is that the block will have a force applied. 1) From the force and mass I calculate the the acceleration vector (will ...
0
votes
1answer
29 views

Why is it easier to catch mosquitoes with your hand when your hand is wet?

Recently I've noticed that it's significantly easier for me to catch a mosquito with my hand if my hand is very wet (e.g. from having washed my hands and not yet dried them, or from being in the ...
-1
votes
0answers
23 views

Time taken to start pure rolling rotational mechanics [closed]

The question deals with the basics of rotational mechanics. A cylinder having radius 0.4 m initially rotating at t=0 with angular velocity =54rad/sec is placed on a rough inclined plane making angle ...
0
votes
3answers
61 views

Friction converting into a heat

On my exam I had following question: bullet with mass $m$ and initial velocity $v_1$ hits wooden board of length $d$ and breaks it through. After that its velocity is $v_2$ and heat generated in a ...
-1
votes
2answers
52 views

Role of friction in rotational motions [on hold]

The problem states that ABC is a curved hemisphere with AB=AC.in AB friction is large whereas BC is smooth.It is left from rest from point A.we have to find that will the ball reach 1.lesser height ...
1
vote
1answer
88 views

How do knife blades become dull?

Knives are normally used to cut softer objects. So the edge of the knifes blade is harder than the substance it cuts through. A blades geometry is more complex, but let's simplify it to the blade ...
0
votes
1answer
24 views

Relation between rain, time and terrains

I would like to understand whether an approximate relation between the rain and the physical properties of a particular terrain (composed of a specific material such as asphalt or clay or grass or ...
0
votes
2answers
49 views

Question about friction

Can there be friction between two contracting surfaces even if they do not slide over each other?
2
votes
2answers
104 views

Why does Friction act Parallel to the Surface (Microscopic Level)?

If we assume an object (blue layer) sliding towards the right across a surface (black layer). According to Newton's 3rd Law, the frictional force would act to the left (resisting the object's relative ...
1
vote
0answers
13 views

Friction and Electric Forces [duplicate]

As I understand, friction arises from electromagnetic forces. Electric fields, at least static ones, exert conservative forces. So how is it that friction is non-conservative?
2
votes
1answer
45 views

Is friction an emergent phenomenon?

The microscopic origin of the frictional forces is due to contact between irregularities of the surfaces as seen here [1]. Electromagnetic interactions are the fundamental forces responsible for ...
2
votes
3answers
54 views

Friction when walking

To meet a U.S. Postal Service requirement, employees’ footwear must have a coefficient of static friction of 0.5 or more on a specified tile surface. A typical athletic shoe has a coefficient of ...
3
votes
1answer
33 views

Problem regarding friction

I require a clarification on some steps in the solution of the following problem. Problem: The coefficient of static friction between two blocks shown in figure is μ and the table is smooth.What ...
1
vote
1answer
26 views

Calculating Rolling Friction in a Lab

What would I have to measure to determine the rolling friction of a model car? Currently, I have the horizontal pulling force that the lab procedure calls for on the car, and enough data to make a ...
1
vote
1answer
35 views

Rubber-Rubber friction

We all know rubber is known to have a high friction coefficient, and it's quite difficult to drag a block of it across a surface. What happens when two blocks of flexible rubber are dragged against ...
0
votes
1answer
22 views

Finding acceleration of a stacked box system, when they are not relative [closed]

Two boxes are stacked, box $A$ is placed on a horizontal surface with no friction, box $B$ is placed on box $A$ with unknown coefficient friction between the two. Box $A$ does not slide relative to ...
2
votes
1answer
41 views

Friction in pulleys

The moment equation of a pulley with a rope applying tension on both sides is as follows: $$I\alpha = f + T_1R - T_2R$$ ( $I$ - moment of inertia; $\alpha$ - angular acceleration; $f$ - friction ...
1
vote
1answer
35 views

How can a rope's tension be at a maximum as a body is about to move up a slope in the rope's direction? [closed]

Note: I do NOT need this exercise's answer. I have no problem working the math out and noticing the truth of my title. A box of mass 0.5 kg is placed on a plane which is inclined at an angle of 40 ...
-1
votes
1answer
56 views

How long would “artificial gravity” remain on an O'Neill cylinder without power? [closed]

An O'Neill Cylinder (as defined by O'Neill, per Wikipedia) has two cylinders which are both "5 miles (8.0 km) in diameter and 20 miles (32 km) long, connected at each end by a rod via a bearing system"...
1
vote
0answers
64 views

Problem with Impure Rolling [closed]

Can someone explain what happens in the below situation Looking at it from the planks frame of reference: The cylinder Velocity= 20(-i) Net friction force on cylinder f=2umg(i) (here u=1/2) ...
1
vote
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, ...
1
vote
0answers
31 views

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 ...
0
votes
1answer
44 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 ...
2
votes
0answers
28 views

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 ...
1
vote
4answers
79 views

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 (...
1
vote
2answers
44 views

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 / ...
2
votes
4answers
898 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 ...
1
vote
1answer
24 views

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 ...
0
votes
2answers
52 views

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 ...
0
votes
1answer
53 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. ...
1
vote
0answers
22 views

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,...
0
votes
1answer
55 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....
0
votes
1answer
49 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 ...
1
vote
3answers
58 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 ...
3
votes
1answer
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 ...
0
votes
1answer
33 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 ...
0
votes
0answers
63 views

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 ...
1
vote
0answers
100 views

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{...
0
votes
1answer
34 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 ...
1
vote
2answers
33 views

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, ...
1
vote
3answers
76 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 ...
0
votes
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 ...
0
votes
1answer
42 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 ...
0
votes
0answers
28 views

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 ...
0
votes
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?
0
votes
1answer
50 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}\...
0
votes
1answer
14 views

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 ...
1
vote
0answers
80 views

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 ...
-3
votes
1answer
35 views

Finding the accelerations of objects [closed]

I want to know how to get the accelerations separately in each object