1. What is the Foot-Pounds Formula?

The Foot-Pounds formula calculates the kinetic energy of a projectile from its weight and velocity. It's commonly used in ballistics to measure the stopping power of ammunition.

2. How Does the Calculator Work?

The calculator uses the Foot-Pounds formula:

Where:

• \( Weight \) — Projectile weight in grains
• \( Velocity \) — Projectile velocity in feet per second (fps)
• 450240 — Conversion factor (2 × gravitational acceleration × 7000 grains per pound)

Explanation: The equation converts the kinetic energy from grain-fps units to foot-pounds, the standard unit for measuring energy in ballistics.

3. Importance of Foot-Pounds Calculation

Details: Foot-pounds energy is crucial for understanding a projectile's stopping power, penetration capability, and effectiveness for different hunting or shooting applications.

4. Using the Calculator

Tips: Enter weight in grains and velocity in feet per second. All values must be valid (weight > 0, velocity > 0).

5. Frequently Asked Questions (FAQ)

Q1: Why use grains for weight measurement?
A: Grains are the standard unit for measuring bullet and projectile weight in ballistics (1 grain = 1/7000 pound).

Q2: What's a typical foot-pounds value for hunting?
A: Minimum recommended values vary by game: small game (100-300 ft-lbs), deer (1000+ ft-lbs), large game (2000+ ft-lbs).

Q3: How does velocity affect energy?
A: Energy increases with the square of velocity, making velocity more significant than weight in energy calculations.

Q4: Are there limitations to this calculation?
A: This calculates theoretical energy at the muzzle. Actual impact energy decreases with distance due to drag.

Q5: What's the relationship between ft-lbs and joules?
A: 1 foot-pound equals approximately 1.3558 joules. Some countries use joules for energy measurement.