why do we needs gears in cars?

Answer 1

for pick up.

Answer 2

Actually you wouldn't need gears if you had enough engine power. Starting form a standstill takes a lot of power, so the car starts in first gear, giving the car a lot of power at the sacrifice of speed. When the car picks up speed inertia helps keeping it rolling, so the car is shifted to second gear. Now you have more speed but less power. In third gear you have still more speed but less power. Rolling along at highway speed you don't need much power. Climbing a steep hill you will need power, so the car ( automatic ) shifts down. Now you can climb the hill, but at a slower speed.

Answer 3

Cars require gears because internal combustion engines operate in a fairly narrow range of speeds -- about 1500 RPM at the low end, and 5000-7000 RPM at the top end. (Some can run faster, but generally this is at the expense of durability). To avoid restricting the speed and power of the car, gearboxes allow various levels of conversion between power or torque and speed.

Electric motors, in contrast, have very flat power bands which react the same way from zero to many thousands of RPM; electric motors are usually connected directly to the wheels of electric vehicles rather than through a transmission system.

Answer 4

We are using different kinds of gear in different engine parts of all automobiles. Gears are primarily a POWER Transmission devices.
When you start your engine it will run in high speeds above 1500 RPM but if you take that much speed to your wheels means your appoinment is fixed with god. At the begining for take off you need more power and lesser speed and later you need less torque and more speed which is governed by this GEARS. For more clear understanding visit this web page

http://en.wikipedia.org/wiki/Gear

Answer 5

Because the gears vary the level of torque multiplication to the drive wheels which assists in efficiency of fuel economy and transmission of power to the road, thus making cars safer.

Answer 6

gears are how things turn. can you think of some things in your car that turn?

Answer 7

this you should remember from when you rode a trickle you see the peddle were in front..

now try riding your bike with the peddles in front (no chain) then look at your bike and see where the chain goes what is does and there is your answer....

Answer 8

Because when you set off you need high torque high rev and low speed, when you are crusing you need high speed at low revs to stop emptying your fuel tank.

Answer 9

We do not, but with it we get batter performance.

Static friction is more then dynamic friction.

Answer 10

so that we don't cause too many road accidents