Definition of what 1 horsepower is

[Dave25]

I have an equation in my study guide that looks like this:

a = F/m = P/v/m = (47 horsepower * 746 W/hp) / (1400kg) (14m/s) = 1.82 m/s^2



My question is, how does my book come up with 746 W/hp? I know why all of the other factors are there, but what numbers were used to get the 746 W/hp. If someone could let me know I would really appreciate it. Thanks.

 

[Dick]

It's the definition of what 1 horsepower is. 1 horsepower=746 watts. So 746 W/hp=1. You basically just look it up.

 

[Dave25]

Hey, thanks. I just read that in my book, I appreciate your help.

 

[Lok]

1 Hp is the power necessary to lift a 75 kg load to a 1 meter height in one second (standard definition). The energy in such a system is E=75kg*1m*g and the power is E/1sec so one Hp is just 75kg*9.8m/s² Watts.