#lbs thrust converts to hp?

whacker1982

heres a pickle of a question, how many lbs of thrust equals to one hp?
and how much electric power amps/volts equals to one pound thrust?

fergal.b

It's too late on a friday night and too many glasses of wine to go into this now:D
To start with thrust and hp are two different things, thrust is a force used to move something even if it won't move, hp is the amount of work done over a certain amount of time by something turning in revolutions per minute.
Roughly 1hp is 75 lbs of thrust but there are a lot of factors that come into play like the prop size,gearbox, friction and drag.
An electric motor that runs on 50 amps with a 12v battery would be 50 x 12 = 600 watts so .8 of a hp as 746 watts = 1 hp

I hope thats helps a bit if not I will come back to it on monday



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whacker1982

nice one fergal, you explained it down to perfection.
my brain is like a sponge in water at the moment for boats and everything to do with boats.

ISAW

From a physics point of vies

Power = force x distance
force = mass x acceleration
Acceleration = velocity /distance squared =M per sec per sec
The SI units are Watts of power Newtons of force meters of length/distance

Mass is kg and

so a watt = 1 newton meter or 1 kg meter per second per second x meter
or kg meter squared per second squared

All units in physics and be reduced to kg meter and seconds
for non SI it is pounds feet and seconds and ergs for newtons foot pounds instead
of newton meters for power


Electricity is measured in culombs C for charge volts V for potential amps I for current

Power W = VxI so you can compare electrical Wattage to engine wattage or horsepower or foot pounds etc.

http://www.aqua-calc.com/convert/power/
http://www.aqua-calc.com/convert/power/foot-pound-per-second-to-watt
http://www.aqua-calc.com/convert/power/horsepower-to-watt
http://www.aqua-calc.com/convert/power/watt-to-horsepower