3. (35 points) Engineers use both English and SI units on a regular basis. Some fields use primarily one or the other, but many combine the two systems. For example, the rate of energy input to a steam power plant from burning fossil fuels is usually measured in Btu/hour. However, the electricity produced by the same plant is usually measured in joules/s (watts). Automobile engines, by contrast, are often rated in horsepower or in (ft. Ibf)/s. Here are some conversion factors relating these different power measurements: u