Question: where is the differential located on a car

title: Differential (mechanical device)
text: Non-automotive uses of differentials include performing analog arithmetic . Two of the differential 's three shafts are made to rotate through angles that represent ( are proportional to ) two numbers , and the angle of the third shaft 's rotation represents the sum or difference of the two input numbers . The earliest known use of a differential gear is in the Antikythera mechanism , circa 80 BCE , which used a differential gear to control a small sphere representing the moon from the difference between the sun and moon position pointers . The ball was painted black and white in hemispheres , and graphically showed the phase of the moon at a particular point in time . See also the Chinese South - pointing chariot . An equation clock that used a differential for addition was made in 1720 . In the 20th Century , large assemblies of many differentials were used as analog computers , calculating , for example , the direction in which a gun should be aimed . However , the development of electronic digital computers has made these uses of differentials obsolete . Military uses may still exist , for example , for a hypothetical computer designed to survive an electromagnetic pulse . Practically all the differentials that are now made are used in automobiles and similar vehicles .