Friction can be increased
Answers
Sandpaper and rough stone would increase friction. Generally, there is more friction when a surface is rough rather than smooth. ... To decrease friction, you canmake the surface smoother, make the objects more streamlined, or reduce the forces acting on the surfaces
OK there are several things you can do to change friction.
❤Change the material. Materials have a different coefficient of friction. Some like Teflon are naturally slippery. Friction causes heat and this can cause things to melt, so the coefficient of friction isn't the only think you need to look at, it is also the conductivity and melting point. Friction happens at the rubbing surface so something like aluminium which has a low melting point is very good at conducting heat away from the friction surface. OBVIOUS STATEMENT WARNING:Generally high friction materials give greater friction
❤Temperarure can change friction. Rubber vehicle tyres are designed to work at different temperatures. If the tyre isn't up to temperature it won't develop enough friction, if it gets too hot it just wears out.
❤Rough surfaces generally have more friction than smooth or better still, polished surfaces.
❤Surface contamination changes friction. Oils, waxes, grease and dry lubricants act as lubricants and carefully cleaning them off increase friction enormously. When brake discs are supplied they are coated in oil to stop them rusting. If you don't clean it off before you drive your brakes won't work well at all. Going the other way, if you add materials that aren't slippy like abrasives between surfaces like train wheels and the tracks it increases traction. Equally weight lifters, gymnasts, pole vaulters and climbers use resins, as indeed string players do on their bows to increase friction
❤Ice is a great lubricant and is low friction. Metal in particular being a good conductor is great for condensing atmospheric moisture sometimes this can freeze resulting in a loss of friction. In some cases cleaning ice of stuff increases friction no end.
❤This is a bit more difficult to get your head round but stuff has more friction when it isn't moving relative to the other surface. This is called static friction, once things begin to slide, the friction drops. This is called sliding friction. If you accelerate in a car, the tyres roll along the surface without slipping. Even though the wheel is turning, it isn't slipping relative to the road. If you hit the accelerator, if the engine is powerful enough, the tyres will just spin up and smoke. If you try and pull away burning out your tyres, you will have less friction than if the tyres aren't spinning against the road. As a result a dragster might do burn outs to make the tyres sticky but on their fast run they apply the power the tyres can handle without breaking traction to get the fastest run. Just flooring it doesn't work. Interestingly the friction area has greater bearing on sliding friction than static friction.