Horsepower, where the term originated.

[sidewaysreilly]

Formula for Calculating Horsepower
Horsepower = 2πrxTORQUE xRPM/ 33000

This formula was established by James Watt in the 1800’s and requires
some known values:
Average horse walks at 2 1/2 MPH
Average horse pulls with a force of 150 pounds
1 mile = 5,280 feet
r = distance from center line of shaft, usually 1 foot
With this background, we will be able to establish the Horsepower formulas
used today.
5,280 feet x 2 1/2 MPH = 13,200 FEET per HOUR
13200 FT/HR /60 minutes= 220 FEET per MINUTE

220 FT/MIN x 150 POUNDS = 33,000 FT LBS per MINUTE
2πr = 6.2831853
3_3_0_0_0 = 5252
6.2831853
Thus we get the familiar formula used today in calculating Hp.
Hp = T_o_r_q_u_e__x__R__P_M_ or expressed another way as
5252
Torque = H__p__x__5_2_5_2_
RPM
The term Brake Horse Power is used to describe an engine/motor which is held against a brake sometimes electrical/hydraulic so that torque can be measured and horsepower calculated.
So there ye all are now ted.

[sidewaysreilly]

sorry, this is in the wrong section........STEVE????????HELLIP.......