1. What is the Horsepower Formula?

Definition: This formula calculates the power output of engines and motors based on torque and rotational speed.

Purpose: It helps engineers, mechanics, and automotive enthusiasts determine engine performance.

2. How Does the Formula Work?

The formula is:

Where:

• \( HP \) — Horsepower (mechanical power)
• \( T \) — Torque (pound-feet)
• \( RPM \) — Rotations per minute
• 5252 — Conversion constant (derived from units)

Explanation: Horsepower is calculated by multiplying torque by rotational speed and dividing by the constant 5252 (which comes from (33,000 ft-lb/min)/2π rad/rev).

3. Importance of Horsepower Calculation

Details: Understanding horsepower helps in engine design, performance tuning, and comparing different motors or engines.

4. Using the Calculator

Tips: Enter torque in pound-feet and RPM (revolutions per minute). Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: Why is the constant 5252?
A: It's derived from the conversion between rotational work and linear work (33,000 ft-lb/min = 1 HP).

Q2: At what RPM does torque equal horsepower?
A: At 5252 RPM, torque and horsepower values are numerically equal (due to the formula).

Q3: Can I use this for electric motors?
A: Yes, this formula works for any rotating machinery where you can measure torque and RPM.

Q4: What's a typical torque value for cars?
A: Passenger cars typically have 100-300 lb-ft torque, while trucks may have 400-1000+ lb-ft.

Q5: How does this relate to kW (kilowatts)?
A: 1 HP = 0.7457 kW. Multiply HP by 0.7457 to convert to kilowatts.