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:
If you have a perfect square that is equal to 1 acre, what is the length of the sides and how do you do it? One acre is 43,560 square feet so a square, with area one acre would have a side if length the square root of 43,560 or approximately 208.71 feet. That is. 208.71feet 208.71feet = 43559.86 square feet. Penny.