# Equation Questions for a gas powered engine driving a pulley system.

1. Apr 8, 2013

### andywingett

I am building a prototype for an agricultural pulley system and I need help calculating how much horse power I need.

The pulley system will need to drag a 400 lbs. object of a 45 degree incline for 150 feet. The static coefficient of friction is 0.1 and the kinetic friction is only 0.05.

According to my calculations the Newtons of force needed to do this is 1322 = 297.19 Pounds Force.

I need to know how much horse power is needed to do this, and the amount of torque that will need to be exerted.

What are the other variables I need to input to solve this?

Last edited: Apr 8, 2013
2. Apr 8, 2013

### SteamKing

Staff Emeritus
How fast do you want to drag the object up the incline?

3. Apr 8, 2013

### andywingett

Three Miles per hour.

4. Apr 9, 2013

### SteamKing

Staff Emeritus
Horsepower = P * V / 550

For your case, V = [3 mph * 5280 ft/mi] / 3600 s/hr = 4.4 ft/sec.

1 hp = 550 ft-lbs/sec.

P = 297.19 lbs

horsepower = 297.19 * 4.4 / 550 = 2.38 hp