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tlktomegoose
April 10, 2022, 08:02 PM
24. A motor is operating at 3450 RPM and is producing a torque of 32 lb-in. What is the output horsepower of the motor?
Your Answer: 21 hp
Correct Answer: 1.75 hp
Help: HP = Torque x RPM ÷ 5252

GrayTard
April 11, 2022, 05:06 AM
24. A motor is operating at 3450 RPM and is producing a torque of 32 lb-in. What is the output horsepower of the motor?
Your Answer: 21 hp
Correct Answer: 1.75 hp
Help: HP = Torque x RPM ÷ 5252

It says lb-in. Your formula is for lb-ft.

tlktomegoose
April 11, 2022, 06:26 AM
It says lb-in. Your formula is for lb-ft.

So to convert lbs per inch to lbs per foot is to multiply by 12 which is 384. Which throws my number way off.

Feyadin
April 11, 2022, 07:56 AM
So to convert lbs per inch to lbs per foot is to multiply by 12 which is 384. Which throws my number way off.

Your conversion is incorrect. Torque isn't measured in pounds per foot (lb/ft). It's measured in pound-foot (lb-ft), which is a concurrent unit, not reciprocal. So, to do the conversion correctly, you would need to divide your initial torque value by 12, not multiply.

tlktomegoose
April 11, 2022, 09:58 AM
Your conversion is incorrect. Torque isn't measured in pounds per foot (lb/ft). It's measured in pound-foot (lb-ft), which is a concurrent unit, not reciprocal. So, to do the conversion correctly, you would need to divide your initial torque value by 12, not multiply.

Awesome! Thank you for the clarity.