# Tag Info

## Hot answers tagged friction

29

Landauer's principle (original paper pdf | doi) expresses a non-zero lower bound on the amount of heat that must be generated by computers. However, this entropy-necessitated heat is dwarfed by the heat generated through ordinary electrical resistance of the circuitry (the same reason light bulbs give off heat).

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Thumbs up for a interesting and curious question. Yes there is worn out due to friction for sure when two surfaces rub along with each other, like you said worn out keyboards are a good example of it. Also, hardness does play an important role in it. Hardness is a physical property and there are different measurements of hardness: scratch hardness, ...

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You almost answered it on your own! Essentially it's the ratio of the viscous force to the gravitational force. As $\beta \rightarrow 0$, the gravitational force dominates and the damping due to air friction is very small. Likewise, as $\beta \rightarrow \infty$, the air friction dominates the solution. This isn't really all that illustrative physically, ...

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Computers manipulate internal stored values "0" and "1" represented as different voltages. Every change 0-to-1 and 1-to-0 involves an electric current I passing through a circuit resistance R, which gives rise to ohmic or "Joule" heating.

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The normal force does decrease with angle. This does not mean that the coefficient of friction changes: We can, depending on the angle $\theta$ of the slope, split the gravitational force $F_g = mg$ acting upon a thing with mass $m$ resting on the slope into the normal force $F_n = mg \cos(\theta)$ and the force pointing down the slope, $F_s = ... 3 In general, smoothing the surface, changing the interaction from sliding to rolling, adding (air) space between the surfaces, and adding lubrication (oil, graphite, teflon, ball bearings, air cushion...) are the most common techniques. 2 Various physical properties of materials including shear strength are connected to the strength of attractive forces between molecules -inter-molecular forces. The type of inter-molecular force determines the force and energy by which the molecules stick to one another. Inter-molecular force types include ionic bonds, hydrogen bonds, dipole forces and ... 2 Integration by parts or using the identity$\frac{d}{dt}\dot{\phi}^2=\dot{\phi}\ddot{\phi}+\dot{\phi}\ddot{\phi}$would be the trick here:$\frac{d\phi}{dt}dt=d\phi$, so:$\int \ddot{\phi} d\phi=\int \ddot{\phi} \dot{\phi} dt=\dot{\phi}^2-\int \ddot{\phi}\dot{\phi}dt$. Applying the usual trick (adding the integral to both sides and dividing by two), this ... 1 No need to involve time in your calculations. If the acceleration is constant, then we know purely from kinematics that $$V_f^2=V_0^2+2a\Delta x,$$ and in this case the final velocity$V_f=0$, so the magnitude of the acceleration is simply $$a=\frac{V_0^2}{2\Delta x}=\frac{F_f}{m}.$$ From the definition of the coefficient of kinetic friction$\mu_k$, we know ... 1 Each page between pages has some static friction force threshold based on the effective coefficient of friction and the normal force compressing them (even if it's just gravity). Like MSalters said, the fact that there are hundred of pages doing this means you have a very large area over which it's applied, but that's not what makes the difference. That ... 1 No, block 1 would move to the right but with smaller acceleration than block 2. You could say it would move to the left relative to the block 2. Yes it would, since block 1 still 'wants' to move to the left relative to the block 2 (the 'relative' part is very important) No it wouldn't, it would be smaller. Block 1 would now move with acceleration that is ... 1 Yes, the force$A$exerts on$B$has to be equal to the one$B$exerts on$A$. And when$F$vanishes the forces between$A$and$B$vanishes too. More specifically, if in the time$F$is acting no movement occurs (i.e.$F$does not overcome the total friction of$A$and$B$) the only thing causing$A$and$B$to interact is$F\$, so this action reaction ...

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This is admittedly a late answer. Hopefully it will clear up some of the confusion. If you ignore aerodynamic drag, ignore that the coefficient of rolling friction varies with load, and ignore a number of other factors such as friction between the axle and the bearings that support it, then yes, stopping time / stopping distance is independent of vehicle ...

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The heat generated in a computer has nothing to do with the reversibility condition in Landauer's principle. Computations can be carried out reversibly, if required. What can not be made reversible is the RESET of the computer. The first time we turn the machine on, the memory is in a random state, and it takes energy and entropy to turn that random state ...

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You're totally correct with the m*a vector! Since the wedge is accelerated and we're assuming that the mass is sort of stuck to it (moves on its surface but stays with the wedge), in a frame of reference attached to the wedge it's going to experience a fictitious inertial force (imagine sitting next to that mass; the bigger the acceleration, the more you'd ...

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I suppose you could try to think of the problem in another way. What would happen to a cylinder (or sphere) if you put it on a frictionless inclined plane? Would it still roll or just slide? The imbalance in forces acting on the cylinder at different points, with respect to its center of mass, are what lead to the rotation. Gravity acts on the center of ...

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I would try to explain very briefly. When you apply a force onto a body, it causes the body to move in the line of application of force. This introduces translational motion into the body. When you apply a torque onto a body, it causes the body to rotate about a point. This introduces rotational motion into the body. Torque in rotation is analogous to ...

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Force represents an energy transfered (and applied in general in a straight line). On the other hand Torque represents a force acting on a point on a straight line but the effects are applied elsewhere (in rotating the body). As such there is (at least) this subtle difference. The force is applied to a point of the body which then (by internal constraints ...

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Friction is an adhesive process. When you touch two surfaces together the atoms at the two surfaces come into contact and form interatomic bonds. In the extreme case of very clean and smooth surfaces you can get cold welding. So reducing static friction is basically a matter of stopping the surfaces from adhering to each other. For example applying a thin ...

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Friction coefficient for ice and ice is minimum. The very high pressure on the ice due to the very narrow blades of the skates causes the ice immediately below the blades to melt. The thin layer of water (melted ice) between the blades and the ice surface reduces the friction between the blades and the ice surface and so the ice skater can glide easily on ...

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