The DC motor was the mainstay of electric traction drives on both electric and diesel-electric locomotives, street-cars/trams and diesel electric drilling rigs for many years. The introduction of DC motors and an electrical grid system to run machinery starting in the 1870s started a new second Industrial Revolution.
One acre is 43,560 sq ft. One half acre is 21,780 sq ft. However, that doesn't help most people much when trying to picture how large a lot is. Half acre lot is roughly:
Best Answer: An acre is equal to 43,560 square feet or 4046.85 m^2, so 1/2 acre = 21,780 square ft (ft^2) An acre is a unit of area, so the length and width can be anything that adds up to 43,560 ft^2. 147.58 ft X 147.58 ft = 21,779.85 ft^2. 100 ft X 217.8 ft = 21,780 ft^2. 5 ft X 4356 ft = 21,780 ft^2.