Mathematical riddle

[PissedGodzilla]

How about we get back to the original question and the nine coins, one is either heavier/lighter but you don't know which... only 3 turns with the scale...


and stop hijacking threads you geeks... lol

Let's dance!!!!!

[bofh]

How about we get back to the original question and the nine coins, one is either heavier/lighter but you don't know which... only 3 turns with the scale...


and stop hijacking threads you geeks... lol

Let's dance!!!!!

Sure, is not much different from the first question. with an extra turn in the middle. if you want, I could PM you the answer, but you'll prolly enjoy it more if you figure it out yourself. Things always feel better when you figure it out without help.

[bofh]

It makes you think of things other than a round piece of rubber, and rather how it is constructed. The point is, although they are all round - there is something structurally different about all of these tires... and I think that's a place to start looking, as far as figuring out why friction is independent from surface area contact - yet there is a different amount of traction.

As with any good "puzzle," They are a success if they make you think in a different way than normal.

[Mister Sinister]

The question of why sports cars tires are wider is not completely answered with the original stated law of psyics. There is much more to it. Miscue brought up a very important point. There are special applications for tires. Sports car tires tend to be short and wide with medium soft rubber and very short stiff sidewalls. Why? So the sidewalls dont flex in hard cornering. Drag car tires are tall and wide. The side walls are very flexible and compound of the rubber is very soft and the air pressure they are filled to is very low. Why? The taller and wider they are the larger contact patch with the ground is. The sidewalls are flexible to absorb shock so the force doesnt cause the tire to spin. Land speed tires are narrow but bald like drag tires, the compounds they are made of are very resistant to heat. The tires are narrow cause they do not need the traction of a drag car. These cars are push started most of the time and not launched. They use narrow so tires so there is less rotating mass to accelerate. Special applications aside what is really defining the width of a tire used is rolling friction not static friction. Some of the added varibles to figuring the coefficent of rolling friction are deformation and adhesion. A good example is drag tires. They use a chemical called VHT it is spayed on the launch pad and the in the burnout box to improve the adhesion. The use of low air pressure allows the tire to deform and spread out. If you have a larger contact patch on the ground the more adhesion you will have hence more traction/friction. If you ever want a scary ride take the same car and drive it in the rain. The wet prevents this adhesion and you slip and slide throw in the soft sidewalls shimmying side to side and well you have one heck of a white knuckle ride. (Yes I have made this mistake before) In summation my answer to your question is they are wider due to increased traction from rolling friction.