eight furlongs are equal to what standard length
Furlong A furlong is a measure of distance in imperial units and U.S. customary units equal to one-eighth of a mile, equivalent to 660 feet, 220 yards, 40 rods, or 10 chains.
Jockey Jockeys must be light to ride at the weights which are assigned to their mounts. There are horse carrying weight limits, that are set by racing authorities. The Kentucky Derby, for example, has a weight limit of 126 lb (57 kg) including the jockey's equipment. The weight of a jockey usually ranges from 108 to 118 lb (49 to 54 kg).[3] Despite their light weight, they must be able to control a horse that is moving at 40 mph (64 km/h) and weighs 1,200 lb (540 kg).[citation needed] Though there is no height limit for jockeys, they are usually fairly short due to the weight limits. Jockeys typically stand around 4 ft 10 in (147 cm) to 5 ft 6 in (168 cm).[3]