Science home learning units research

The interesting unit that I am going to talk about is horsepower. Everytime you see sports cars in newspapers and magazines they would always indicate a "horsepower". It is refering to the power of the car. So, since they are cars, why horsepower and not carpower? Well, that is what I am going to talk about. The word horsepower originally came from the time when steam engines were first invented, replacing the previous horses. People at that time did not know what to compare speed to, and thus compared it to the only form of speed they knew, the horse's speed. They estimated how much power a horse can have and compare it to their new steam engines. The mechanical horsepower of 550 foot-pounds per second is approximately equivalent to 745.7 watts. The unit was not accepted as a SI unit as the definition of the unit varied between geographical regions. Horsepower is useful as the horse is fast, and therefore it is easy to compare with our vehicles now but the disadvantage is that we cannot compare all machineries with the horsepower as even though the horse is fast, our jet planes are far more faster and we therefore cannot compare them. However, it is still useful as it is widely known and can be easily understood by others.