Kako funkcioniraju bicikli?
Millions of people around the world use bicycles. People ride their bikes to exercise, commute, deliver packages, compete in races or just ride for fun. Cycling may seem easy to some, but it's actually quite complicated. Both the rider and the bike play an integral role in the process, which is actually more of a science than an art. How does this two-wheeled object drive?
Sastav bicikla
Okvir bicikla, sistem ručki (uključujući prednju viljušku, grip), okvir bicikla, prednji i zadnji točkovi, sistem lanaca, kočnice, blatobrane, zvona i ostali dodaci, sportski bicikli takođe imaju prednji i zadnji sistem menjanja.
Kako rade kočnice bicikla
Bez obzira koliko brzo pedalirate, uvijek morate stati. Kočnice na biciklima rade pomoću trenja. Dok su neki bicikli sada opremljeni disk kočnicama, mnogi još uvijek koriste tradicionalne kočnice na felgi-stilu s cipelama.
Kakobicyclehandlebarswork
Upravljač bicikla je zapravo vrsta poluge. Duži upravljači pružaju polugu, što olakšava okretanje prednjeg točka bicikla. Što više razmaknete ruke, stvarate veći otpor zraka. Tipični vanjski dijelovi upravljača služe za upravljanje, a unutrašnji dijelovi za klizanje.
Kakobiciklokvirni rad
Admittedly, if a person weighing 140–170 pounds uses the bike, the bike must not be damaged. This means that the frame of the bike has to be very stiff. With traditional bikes, the frame is made of strong, cheap tubular steel (actually hollow steel tubes with nothing but air in them) or lighter steel or aluminum alloys.
Mnogi ljudi mogu pomisliti da bi okvir bicikla napravljen od aluminijskih cijevi bio mnogo slabiji od čeličnog okvira. Ovo vrijedi samo ako su cijevi slične veličine. Zapravo, svaki bicikl mora biti dovoljno jak da izdrži velike težine. Stoga će aluminijski bicikl koristiti cijev većeg promjera ili deblju od čeličnog bicikla.
Kako btočkovi za biciklerad
Pošto svaki točak ima 24 kraka, u praksi oni nose neravnomernu težinu. Konkretno, žbice koje se nalaze blizu vertikale su podvrgnute mnogo većem opterećenju od ostalih žbica kada se točak rotira.
The closer the spokes move to the vertical, the more deformation it is subjected to. The load that each spoke is subjected to increases and decreases dramatically with each revolution of the wheel. After thousands of such cycles over and over again, one of the spokes may fail. That causes an immediate increase in the load on the remaining spokes. As such, they are more likely to be damaged by a kind of "domino" effect. As a result, the bicycle wheel will be warped.
A wheel and the axis it rotates around is a good example of the "simple machine" that scientists often refer to. Bicycle wheels are typically over 50 centimeters (20 inches) in diameter, taller than most car wheels, and it multiplies force or speed depending on how you spin it. The higher the wheels, the faster they spin. That is why racing bike wheels have the largest diameter (about 70cm or 27.5 inches).
Kakobiciklistička oprema rad
The gears are chain-linked so you can ride faster (down a straight line) or easier (uphill). It is also an example of a simple machine. Gears can make amazing changes in your speed. For example, if the gear ratio on a race car is 5:1, one lap of the pedals will take you about 35 feet (10m) on the street. When you ride a bike, the pedaling force you generate causes the bike's gears to turn the rear wheel.
This deceptively simple two-wheeled machine harnesses momentum, force and friction and converts that energy into the power that gets the rider to his destination. Whether you're teaching the physics of a bicycle or a class with a simple machine, there are many exercises you can learn on the bike.
