Science behind how gears work?

Question

Can you please describe the science behind how gears work please (try to use science words about forces and energy please) thanks in advance

Answer 1

Think of them as circular levers.

Answer 2

if you have seen the gear box say having 4 gears  forward and one reverse gear.IF you put clutch , the gear of 1 is moved in a position now quickly 2nd gear is fixed then the speed increases because meshing takes place with more gears  come in and similarly clutch if uced and higher number of teeth get entered to increase speed

reverse also with most lesser teeth engged in a reverse order whre the veh goes back.

principasl is more teeth moves for more speed torque increses, lesser teeth slows down

Answer 3

Have a look in this site

http://auto.howstuffworks.com/gears.htm